(CNN) -- A study released this week revealed that 47% of Facebook users have swear words on their pages. A survey last week, meanwhile, showed that undergraduate men who talk about alcohol on Facebook tend to have more friends.
Whether it's our level of tolerance for swearing or the link between alcohol and bonding with friends, these Facebook studies provide intriguing insights into our online behaviors.
And yet I'd argue that Facebook surveys have a more fundamental role. With more than 600 million people actively using Facebook, these studies in fact provide a deeper understanding of our evolving cultural norms: our values, our morals and our changing relationships between one another.
Don't believe me? Here are some fascinating Facebook facts that just might serve as a peek into our 21st-century values.
1. 56% of Americans think it's irresponsible to friend your boss on Facebook
A survey released in February 2010 showed the majority of Americans don't find it socially acceptable to be Facebook friends with their boss. The study of 1,000 people by Liberty Mutual's Responsibility Project suggests that despite an increasing overlap between our work and home lives, we continue to value a separation between the two.
Meanwhile, 62% of those surveyed said it's wrong for a manager to befriend an employee on Facebook. And yet 76% of respondents said it was acceptable to befriend a peer on Facebook, suggesting what we truly value is that our work be judged on its merits rather than getting ahead based on personal relationships.
2. Facebook links about sex are shared 90% more than average
Facebook confirms the adage: Sex sells. From February until May 2010, social media scientist Dan Zarrella processed 12,000 links to news sites and blogs. He discovered that links about sex were 90% more likely to be shared on Facebook than any other subject matter.
He also discovered that links with positive sentiment were more likely to be shared on Facebook than those with negative viewpoints.
3. People in Facebook relationships are happier than single people
In February 2010, Facebook marked Valentine's Day by comparing the relationship status of its users to their happiness -- this was surmised based on the level of positive or negative sentiment in the user's Facebook updates.
The result: Those in relationships were found to be slightly happier than single people. Those who were married or engaged were also happier than single people on average.
However, Facebook users in an "open relationship" -- where the partners are not exclusive to one another -- were significantly less happy than single people. Monogamy, it seems, makes us happy.
4. 21% of people would break up via Facebook
A June 2010 survey of 1,000 Facebook users -- 70% of whom were male -- found that 25% had been "dumped" via Facebook (via their significant other updating his or her relationship status).
Twenty-one percent of those surveyed said they would end a relationship by changing their Facebook relationship statuses to "single." While worrisome, the survey does show the majority of people do not split up via Facebook.
For this uncomfortable task, it seems, we still turn to more personal forms of communication. This particular study also appears to suffer from a little male bias -- a July 2010 survey found that 9% of women have initiated a breakup via Facebook, versus 24% of men.
5. 85% of women are annoyed by their Facebook friends
For women on Facebook, friends can sometimes be irritating. In a March study conducted by Eversave, 85% admitted to having been annoyed by their Facebook friends. Of these annoyances, the most cited was "complaining all the time" (63%).
Other pet peeves included "sharing unsolicited political views" (42%) and "bragging about seemingly perfect lives" (32%).
While I've yet to see a similar survey focused on men, it's probably safe to assume these feelings are universal: Our friends are a source of joy and occasional irritation.
6. 25% of households with a Facebook account don't use privacy controls
A June 2010 survey from Consumer Reports stated that "in one of four households with a Facebook account, users weren't aware of or didn't choose to use the service's privacy controls."
While Consumer Reports chose to interpret this finding in a negative light, I'd propose a contrary view: Seventy-five percent of households did take the time to understand Facebook's privacy controls, suggesting that privacy remains important to our society.
The same study stated that "Twenty-six percent of Facebook users with children had potentially exposed them to predators by posting the children's photos and names."
Again, the positive view would be that 74% of Facebook users with children did not post their photos and names -- suggesting that we value privacy.
7. 48% of parents friend their kids on Facebook
On the question of whether it's OK to friend your kids on Facebook, parents are roughly split down the middle -- 48% have chosen to do so. Respondents in a May 2010 survey by Retrevo admitted that this could be "awkward at times."
Parents were also asked about the minimum age at which their children should be allowed to sign up for Facebook or MySpace. Twenty-six percent of parents replied "over 18," 36% said "16 to 18," 30% said "13 to 15" and 8% said "under 13."
Opinions may be changing rapidly, however. A Consumer Reports survey released this month says the majority of parents of kids 10 and under "seemed largely unconcerned by their children's use" of Facebook.
8. 47% of Facebook users have profanity on their walls
As previously mentioned, a new study by the reputation management service Reppler has found that 47% of Facebook users have swear words on their walls, with these profanities being posted by a friend 56% of the time.
In other words: Nearly half of Facebook users are comfortable with swearing. The most common profanity on Facebook? No prizes for guessing: It's the "F-word."
9. 48% of people say they look at their ex's Facebook profile too often
In a January study by YouTango, 48% of respondents said they look at their ex's Facebook or other social-networking profile too often. The statistic illustrates one danger of social-networking profiles -- ex-partners are more accessible than ever.
But the survey also points to a degree of self-awareness among the respondents. While new technologies provide new temptations, it seems that many of us are able to control these behaviors.
10. 36% of under-35s check Facebook, Twitter or texts after sex
An October 2009 study by Retrevo suggested that social networks are becoming an increasingly important part of young people's lives. Among under-35s, 36% admitted to "tweeting, texting and checking Facebook after sex." Forty percent of respondents admitted to doing so while driving, 64% said they do so at work, and 65% use these communication channels while on vacation.
Here, we might conclude that the next generation is driving society into a less desirable direction: a world in which digital devices are never put down, even in the most inappropriate of situations.
And yet if Facebook is our guide, I'd say our cultural norms have remained intact. We continue to value professionalism. We find great rewards in human relationships -- and most of us try to exit them honorably.
On the whole, we continue to value privacy. We try to look out for our kids. And as we have been since time immemorial, we continue to be fascinated by sex -- after which we go straight to Facebook to find out what our exes are up to.
Tuesday 31 May 2011
Research shows ways to make iPad apps more user-friendly
Editor's note: Amy Gahran writes about mobile tech for CNN.com. She is a San Francisco Bay Area writer and media consultant whose blog, Contentious.com, explores how people communicate in the online age.
(CNN) -- There's a learning curve for every new consumer technology -- both for people who use the device and for makers of software or services that run on it. This has definitely been the case for Apple's iPad, which hit the market just over a year ago.
According to new research from Nielsen Norman Group (NNG), the usability of iPad apps and of Web sites displayed on this device have improved substantially in the past year. In particular, "apps have become more consistent and standardized, making them easier to use," NNG said.
But there's still plenty of room for improvement.
NNG brought in 16 people with at least two months' experience using the iPad and systematically tested how they interacted with 26 iPad apps and six Web sites.
Here's what they learned, based on users' feedback, preferences and complaints:
Touchable areas are often too small, too close, not easy enough to discern.
Often, text content is big enough to read, but links in the text are too small to tap easily. Similarly, sites and apps that have too many touchable areas too close together increase the risk of touching the wrong one.
This leads to navigational accidents, which can be especially vexing in iPad apps that lack a "back" button. Also, many touchable areas don't look obviously touchable, so users tend to miss them.
Similarly, "swipe ambiguity plagued users when multiple items on the same screen could be swiped. Carousels often caused this usability problem in apps that also relied on swiping to move between pages. Many users couldn't turn the page because they swiped in the wrong spot. Their typical conclusion? The app is broken."
iPad users dislike typing on the touchpad.
This presents a variety of issues, including that fewer iPad users are likely to go through a registration process that requires lots of onscreen typing. This may partly explain why the iPad has a reputation at being not so great for media creation. "(iPad use is) heavily dominated by media consumption, except for the small amount of production involved in responding to e-mails."
The Web browser has its limits.
It's good for simpler tasks, not so good for complex tasks. NNG's advice: "If your service requires substantial interaction, consider an app instead of a site."
In contrast, simpler tasks tend to work well in the iPad browser: "In our testing, a few tasks were performed both on the Web and using an application. In these cases, our participants were always successful on the Web. A third of the corresponding tasks that involved apps ended in failure." Usually, this was because the Web site contained more information than the app, or the app design was confusing.
NNG noted: "Whenever apps lack features, users quit them for the websites."
Use of screen space is inefficient.
"Many apps use the (relatively) big iPad screen inefficiently: the screen contains little information, and users have to take extra actions to get to the content."
Also, "Popovers are frequent culprits for underutilizing (screen) space. Too often we see relevant content crammed in a small popover window, while all the other space underneath remains unused."
People prefer landscape mode, barely.
"Slightly more users mentioned that they preferred the landscape (horizontal) orientation for the iPad. A seemingly related factor was whether they were using an iPad cover; those who did mentioned that they often propped their iPad up in landscape orientation."
One problem NNG noted was that some iPad apps handle navigation differently depending on orientation: "For instance, they use horizontal navigation in landscape and use vertical navigation in portrait." This can confuse users.
Some apps even offer different content depending on orientation. For instance, BBC News' app lists different sections in landscape and in portrait orientation. This is especially likely to confuse or annoy users, since users are more likely to switch orientations in a single session while in magazine or news apps.
iPad users are more leisurely about kill time.
"Killing time is the other major use for smartphones, and that is shared with the iPad. ... (However,) the uses are slightly different. The time that is usually available on the smartphone is much shorter and more fragmented than the one available on the iPad.
"On the smartphone, users may look for a quick article to kill the three minutes of waiting for the train; once on the train, they may take out the iPad for the hour it takes them to ride home. As one user put it: 'I am not in a rush when I use this device.' "
Die, splash screens, die.
"We thought we had driven a stake through splash screens many years ago and eradicated them from the Web, but apparently splash screens are super-vampires that can haunt users from beyond the grave. Several new iPad apps have long introductory segments that might be entertaining the first time, but soon wear out their welcome. Bad on sites, bad in apps. Don't."
(CNN) -- There's a learning curve for every new consumer technology -- both for people who use the device and for makers of software or services that run on it. This has definitely been the case for Apple's iPad, which hit the market just over a year ago.
According to new research from Nielsen Norman Group (NNG), the usability of iPad apps and of Web sites displayed on this device have improved substantially in the past year. In particular, "apps have become more consistent and standardized, making them easier to use," NNG said.
But there's still plenty of room for improvement.
NNG brought in 16 people with at least two months' experience using the iPad and systematically tested how they interacted with 26 iPad apps and six Web sites.
Here's what they learned, based on users' feedback, preferences and complaints:
Touchable areas are often too small, too close, not easy enough to discern.
Often, text content is big enough to read, but links in the text are too small to tap easily. Similarly, sites and apps that have too many touchable areas too close together increase the risk of touching the wrong one.
This leads to navigational accidents, which can be especially vexing in iPad apps that lack a "back" button. Also, many touchable areas don't look obviously touchable, so users tend to miss them.
Similarly, "swipe ambiguity plagued users when multiple items on the same screen could be swiped. Carousels often caused this usability problem in apps that also relied on swiping to move between pages. Many users couldn't turn the page because they swiped in the wrong spot. Their typical conclusion? The app is broken."
iPad users dislike typing on the touchpad.
This presents a variety of issues, including that fewer iPad users are likely to go through a registration process that requires lots of onscreen typing. This may partly explain why the iPad has a reputation at being not so great for media creation. "(iPad use is) heavily dominated by media consumption, except for the small amount of production involved in responding to e-mails."
The Web browser has its limits.
It's good for simpler tasks, not so good for complex tasks. NNG's advice: "If your service requires substantial interaction, consider an app instead of a site."
In contrast, simpler tasks tend to work well in the iPad browser: "In our testing, a few tasks were performed both on the Web and using an application. In these cases, our participants were always successful on the Web. A third of the corresponding tasks that involved apps ended in failure." Usually, this was because the Web site contained more information than the app, or the app design was confusing.
NNG noted: "Whenever apps lack features, users quit them for the websites."
Use of screen space is inefficient.
"Many apps use the (relatively) big iPad screen inefficiently: the screen contains little information, and users have to take extra actions to get to the content."
Also, "Popovers are frequent culprits for underutilizing (screen) space. Too often we see relevant content crammed in a small popover window, while all the other space underneath remains unused."
People prefer landscape mode, barely.
"Slightly more users mentioned that they preferred the landscape (horizontal) orientation for the iPad. A seemingly related factor was whether they were using an iPad cover; those who did mentioned that they often propped their iPad up in landscape orientation."
One problem NNG noted was that some iPad apps handle navigation differently depending on orientation: "For instance, they use horizontal navigation in landscape and use vertical navigation in portrait." This can confuse users.
Some apps even offer different content depending on orientation. For instance, BBC News' app lists different sections in landscape and in portrait orientation. This is especially likely to confuse or annoy users, since users are more likely to switch orientations in a single session while in magazine or news apps.
iPad users are more leisurely about kill time.
"Killing time is the other major use for smartphones, and that is shared with the iPad. ... (However,) the uses are slightly different. The time that is usually available on the smartphone is much shorter and more fragmented than the one available on the iPad.
"On the smartphone, users may look for a quick article to kill the three minutes of waiting for the train; once on the train, they may take out the iPad for the hour it takes them to ride home. As one user put it: 'I am not in a rush when I use this device.' "
Die, splash screens, die.
"We thought we had driven a stake through splash screens many years ago and eradicated them from the Web, but apparently splash screens are super-vampires that can haunt users from beyond the grave. Several new iPad apps have long introductory segments that might be entertaining the first time, but soon wear out their welcome. Bad on sites, bad in apps. Don't."
Thursday 26 May 2011
Google Expects the Online Advertising Market to Grow
According to reports, Google has no doubt that online advertising is here to stay. Not only is it here to stay, but it is going to continue to grow. The vice president of display advertising at Google, Neal Mohan, says that display advertising is actually influencing the way people search.
Mohan went on to say that the digital display sector is currently a $24 billion market. However, he feels that it has so much more room to grow. In fact, he thinks that this sector can easily reach $200 billion a year. Now he understands that this is a long way to go, but he said that the opportunity is clearly there.
Of course, other companies are not prepared to give Google all the glory. In fact, some marketing groups, like WPP, are currently watching the digital display industry very closely. To WPP, online advertising has been the best way to offset ever declining sales of offline advertising. However, since WPP is attempting to really make a name with online advertising, it sees Google as a friend and an enemy. The chief executive of WPP, Sir Martin Sorrell, said that Google is a “frenemy” to his company. He said that Google is a threat, but it also helps represent a lot of opportunity as well.
However, others were not as nice to Google as Martin was. In fact, former ITV chief executive Michael Grade had nothing nice to say about Google at all. In fact, he went on to say that Google is nothing more than a parasite. However, Mr Mohan came to Google’s aid and defended the company against this strong criticism. He said that Google is in the technology sector, not the media business sector. He said that Google, in no way, owns inventory; they are not a media company. Mohan said that Google can not execute unless advertisers buy into the system and adopt it.
Mohan did not stop there. He said that Google, by helping to grow the digital display market, can help give media companies a “leg up.” Overall, the whole company does feel like there is a tremendous opportunity here. This is not just an opportunity for Google, but for the whole media industry.
Of course, it is hard for some companies to want to get on board with Google – mostly because Google has already grown so big. Google is one of those companies that has its hands in a ton of different markets, and it is doing it successfully. A lot of other companies find this kind of thing intimidating.
The real question for Google is: Where does it go from here? With the success of Android, the company has successfully made it’s way into the operating system industry. Does Google plan on expanding this? Will people someday see Google operating systems on home computers? Only time will tell.
Mohan went on to say that the digital display sector is currently a $24 billion market. However, he feels that it has so much more room to grow. In fact, he thinks that this sector can easily reach $200 billion a year. Now he understands that this is a long way to go, but he said that the opportunity is clearly there.
Of course, other companies are not prepared to give Google all the glory. In fact, some marketing groups, like WPP, are currently watching the digital display industry very closely. To WPP, online advertising has been the best way to offset ever declining sales of offline advertising. However, since WPP is attempting to really make a name with online advertising, it sees Google as a friend and an enemy. The chief executive of WPP, Sir Martin Sorrell, said that Google is a “frenemy” to his company. He said that Google is a threat, but it also helps represent a lot of opportunity as well.
However, others were not as nice to Google as Martin was. In fact, former ITV chief executive Michael Grade had nothing nice to say about Google at all. In fact, he went on to say that Google is nothing more than a parasite. However, Mr Mohan came to Google’s aid and defended the company against this strong criticism. He said that Google is in the technology sector, not the media business sector. He said that Google, in no way, owns inventory; they are not a media company. Mohan said that Google can not execute unless advertisers buy into the system and adopt it.
Mohan did not stop there. He said that Google, by helping to grow the digital display market, can help give media companies a “leg up.” Overall, the whole company does feel like there is a tremendous opportunity here. This is not just an opportunity for Google, but for the whole media industry.
Of course, it is hard for some companies to want to get on board with Google – mostly because Google has already grown so big. Google is one of those companies that has its hands in a ton of different markets, and it is doing it successfully. A lot of other companies find this kind of thing intimidating.
The real question for Google is: Where does it go from here? With the success of Android, the company has successfully made it’s way into the operating system industry. Does Google plan on expanding this? Will people someday see Google operating systems on home computers? Only time will tell.
Wednesday 25 May 2011
Watch Out, Nook: Amazon Launches $164 Kindle 3G With Ads
(MASHABLE) Watch out, Nook: Amazon has just launched a 3G version of its ad-supported Kindle for $164.
The new device, officially called the Kindle 3G With Special Offers, is almost identical to the $114 ad-supported Wi-Fi Kindle except for the addition of 3G functionality. The device is a 6-inch device that displays the occasional advertisement. In return, users get special offers and a $25 discount on the Kindle 3G’s $189 price tag. In a statement, Amazon Kindle director Jay Marine called it “the lowest price for any 3G ereader.”
The special deals associated with the 3G Kindle are similar to the Wi-Fi version. Some of the special offers Amazon will launch “in the coming weeks” include $10 for a $20 Amazon gift card, 20% discounts on 200 HDTVs, and $1 for select Kindle books.
The announcement of the Kindle 3G With Special Offers comes just hours after Barnes & Noble unveiled its $139 touchscreen Nook, a Wi-Fi-only ereader device that is lighter than the Kindle and boasts two months of battery life. Barnes & Noble also claims that it controls 25% of the ebook market, something that can’t be sitting well with Amazon
The new device, officially called the Kindle 3G With Special Offers, is almost identical to the $114 ad-supported Wi-Fi Kindle except for the addition of 3G functionality. The device is a 6-inch device that displays the occasional advertisement. In return, users get special offers and a $25 discount on the Kindle 3G’s $189 price tag. In a statement, Amazon Kindle director Jay Marine called it “the lowest price for any 3G ereader.”
The special deals associated with the 3G Kindle are similar to the Wi-Fi version. Some of the special offers Amazon will launch “in the coming weeks” include $10 for a $20 Amazon gift card, 20% discounts on 200 HDTVs, and $1 for select Kindle books.
The announcement of the Kindle 3G With Special Offers comes just hours after Barnes & Noble unveiled its $139 touchscreen Nook, a Wi-Fi-only ereader device that is lighter than the Kindle and boasts two months of battery life. Barnes & Noble also claims that it controls 25% of the ebook market, something that can’t be sitting well with Amazon
Thursday 19 May 2011
Apple readying Web music service, report says
(CNN) -- Apple has dominated digital music sales for years with its iTunes store, which allows shoppers to download songs and other content.
Now it's looking increasingly likely that the leading tech company will enter the growing music-streaming market as well.
Apple has signed a cloud-music licensing agreement with EMI Music and is close to completing deals with two other music labels, according to a report by tech news site CNET, citing multiple music industry sources.
Such a product would throw Apple into direct competition with Amazon and Google, both of which recently launched cloud-based music streaming services of their own. Such services store songs on Web servers, where they are accessible from any device with an Internet connection, instead of on a user's hard drive.
Apple signed a similar licensing deal with Warner Music last month. Its negotiations with Sony Music Group and Universal Music Group, the remaining of the four major labels, could be wrapped up as early as next week, CNET reports.
Apple did not immediately respond to a request for comment by CNN.
Record labels, seeking to maintain revenue in the struggling music industry, have maintained that streaming music requires a license that is separate from offering songs for sale. But both Amazon and Google launched their cloud-based services without any licensing deals in place.
By cooperating with the music industry on licensing songs, Apple would stake out a different position from its rivals. This could give an Apple music-streaming product a leg up on the competition, writes MG Siegler for TechCrunch:
"So the labels, which for the better part of a decade now have been looking for someone, anyone to help counter Apple's power in their business, is turning right back to Apple when they need help. And Apple will obviously gladly welcome them with open arms. After all, with these licenses, Apple will have secured the cloud music high ground despite being the last to launch," he writes.
"Think about it. With these agreements, Apple is likely going to be able to do the one thing that is absolutely crucial for cloud music to take off: offer library syncing without uploading.
"In other words, Apple now likely be able to do what Lala (the company Apple bought in late 2009 and subsequently shut down) was able to do: scan your hard drive for songs and let you play those songs from their servers without having to upload them yourself."
Google's Music Beta, announced earlier this month, lets users upload their music to Google's servers and migrate their playlists and data from iTunes. The music player can be accessed from a Web browser as well as from an Android phone or tablet, and users can add up to 20,000 songs for free.
That followed Amazon's launch in March of its rival Cloud Player, which lets consumers upload their music to Amazon's servers and play them via the Web or Android. Users are given 5 GB of free storage but must pay for additional space.
Now it's looking increasingly likely that the leading tech company will enter the growing music-streaming market as well.
Apple has signed a cloud-music licensing agreement with EMI Music and is close to completing deals with two other music labels, according to a report by tech news site CNET, citing multiple music industry sources.
Such a product would throw Apple into direct competition with Amazon and Google, both of which recently launched cloud-based music streaming services of their own. Such services store songs on Web servers, where they are accessible from any device with an Internet connection, instead of on a user's hard drive.
Apple signed a similar licensing deal with Warner Music last month. Its negotiations with Sony Music Group and Universal Music Group, the remaining of the four major labels, could be wrapped up as early as next week, CNET reports.
Apple did not immediately respond to a request for comment by CNN.
Record labels, seeking to maintain revenue in the struggling music industry, have maintained that streaming music requires a license that is separate from offering songs for sale. But both Amazon and Google launched their cloud-based services without any licensing deals in place.
By cooperating with the music industry on licensing songs, Apple would stake out a different position from its rivals. This could give an Apple music-streaming product a leg up on the competition, writes MG Siegler for TechCrunch:
"So the labels, which for the better part of a decade now have been looking for someone, anyone to help counter Apple's power in their business, is turning right back to Apple when they need help. And Apple will obviously gladly welcome them with open arms. After all, with these licenses, Apple will have secured the cloud music high ground despite being the last to launch," he writes.
"Think about it. With these agreements, Apple is likely going to be able to do the one thing that is absolutely crucial for cloud music to take off: offer library syncing without uploading.
"In other words, Apple now likely be able to do what Lala (the company Apple bought in late 2009 and subsequently shut down) was able to do: scan your hard drive for songs and let you play those songs from their servers without having to upload them yourself."
Google's Music Beta, announced earlier this month, lets users upload their music to Google's servers and migrate their playlists and data from iTunes. The music player can be accessed from a Web browser as well as from an Android phone or tablet, and users can add up to 20,000 songs for free.
That followed Amazon's launch in March of its rival Cloud Player, which lets consumers upload their music to Amazon's servers and play them via the Web or Android. Users are given 5 GB of free storage but must pay for additional space.
Wednesday 18 May 2011
Monday 16 May 2011
Sunday 15 May 2011
Monday 9 May 2011
t Brightly Colored Bird Feathers Inspire New Kind of Laser
A new kind of laser captures light just like some colorful bird feathers. The device mimics the nanoscale structure of colorful feathers to make high-intensity laser light with almost any color.
Lasers work by trapping light in or near a material that can emit more photons with the same wavelength, or color. Incoming photons excite the atoms in the material, and make them spit out more identical photons. But to get enough photons for a bright beam of laser light, the photons need to hang around in the material for a long time.
One way to buy time for photons is by forcing them to bounce back and forth. Traditional lasers do this by bouncing the photons between two mirrors. In recent years, physicists have built lasers from slabs of specialized glass with air holes drilled in them. Light can get trapped on a particular path between the holes, and bounce around long enough to make laser light.
Physicists have tried arranging the holes in both tightly ordered and completely random patterns. But both of those options had drawbacks — ordered lasers only work at one wavelength and are expensive to build, and random lasers aren’t very efficient.
Physicist Hui Cao of Yale and colleagues tried something in between: an arrangement of holes that looks random from afar but has pockets of order up close. This is similar to the setup of air pockets in bird feathers.
Certain brightly colored birds, like kingfishers or parrots, have feathers embedded with a not-quite-random arrangement of air pockets. Wavelengths of light that are related to the distance between the air pockets get scattered and built up more than others, giving the feathers their characteristic colors.
“After we learned this, we said, ‘Oh, that’s a smart idea!’” Cao said. “Can we use this to improve our lasers? Maybe we can use short-range order to enhance light confinement and make lasing more efficient.”
Cao’s team drilled holes in a 190-nanometer-thin sheet of gallium arsenide, a special sort of plastic that transmits light efficiently and is commonly used in optics. The holes were spaced between 235 and 275 nanometers apart. The plastic included a layer of equally spaced quantum dots, which emit lots of light when struck with one photon. When light entered the plastic, the physicists reasoned, it should bounce around between the holes long enough to make the quantum dots produce enough photons to start lasing.
When the researchers lit up the tiny wafer, it produced laser light with wavelengths of about 1,000 nanometers, in the near-infrared range of the electromagnetic spectrum. It was much more efficient than random lasers. The researchers also found that they could change the wavelength of the laser light by changing the spacing between the holes.
“Just like the birds, who can tune their short-range order to get different color from their feathers. We can do the same thing,” Cao said.
Cao doesn’t have any particular applications in mind for this tunable, efficient laser. But she points out that by giving up on long-range order, her laser is much cheaper and easier to build than previous models.
“We can have control, and it doesn’t have to be perfect,” she said. “That’s what we learned from nature.”
Cao and colleagues are now trying to use actual bird feathers as a template. They hope to embed tiny semiconductors in the air holes and dissolve away the keratin that holds them together. This might be an easier way to make lasers with extremely short wavelengths, in the blue or ultraviolet range.
It might be even more interesting to figure out how the birds build their feathers in the first place, said biologist Matt Shawkey of the University of Akron in Ohio.
“Birds seem to do it very cheaply. They have thousands of these feathers,” he said. “If you can get these things to build themselves, taking the painstaking process out, then you’d barely have to put any energy and time into it. It would be really cool to see which parameters the birds are changing to get these feathers to self-assemble.”
(WIRED.COM)
Lasers work by trapping light in or near a material that can emit more photons with the same wavelength, or color. Incoming photons excite the atoms in the material, and make them spit out more identical photons. But to get enough photons for a bright beam of laser light, the photons need to hang around in the material for a long time.
One way to buy time for photons is by forcing them to bounce back and forth. Traditional lasers do this by bouncing the photons between two mirrors. In recent years, physicists have built lasers from slabs of specialized glass with air holes drilled in them. Light can get trapped on a particular path between the holes, and bounce around long enough to make laser light.
Physicists have tried arranging the holes in both tightly ordered and completely random patterns. But both of those options had drawbacks — ordered lasers only work at one wavelength and are expensive to build, and random lasers aren’t very efficient.
Physicist Hui Cao of Yale and colleagues tried something in between: an arrangement of holes that looks random from afar but has pockets of order up close. This is similar to the setup of air pockets in bird feathers.
Certain brightly colored birds, like kingfishers or parrots, have feathers embedded with a not-quite-random arrangement of air pockets. Wavelengths of light that are related to the distance between the air pockets get scattered and built up more than others, giving the feathers their characteristic colors.
“After we learned this, we said, ‘Oh, that’s a smart idea!’” Cao said. “Can we use this to improve our lasers? Maybe we can use short-range order to enhance light confinement and make lasing more efficient.”
Cao’s team drilled holes in a 190-nanometer-thin sheet of gallium arsenide, a special sort of plastic that transmits light efficiently and is commonly used in optics. The holes were spaced between 235 and 275 nanometers apart. The plastic included a layer of equally spaced quantum dots, which emit lots of light when struck with one photon. When light entered the plastic, the physicists reasoned, it should bounce around between the holes long enough to make the quantum dots produce enough photons to start lasing.
When the researchers lit up the tiny wafer, it produced laser light with wavelengths of about 1,000 nanometers, in the near-infrared range of the electromagnetic spectrum. It was much more efficient than random lasers. The researchers also found that they could change the wavelength of the laser light by changing the spacing between the holes.
“Just like the birds, who can tune their short-range order to get different color from their feathers. We can do the same thing,” Cao said.
Cao doesn’t have any particular applications in mind for this tunable, efficient laser. But she points out that by giving up on long-range order, her laser is much cheaper and easier to build than previous models.
“We can have control, and it doesn’t have to be perfect,” she said. “That’s what we learned from nature.”
Cao and colleagues are now trying to use actual bird feathers as a template. They hope to embed tiny semiconductors in the air holes and dissolve away the keratin that holds them together. This might be an easier way to make lasers with extremely short wavelengths, in the blue or ultraviolet range.
It might be even more interesting to figure out how the birds build their feathers in the first place, said biologist Matt Shawkey of the University of Akron in Ohio.
“Birds seem to do it very cheaply. They have thousands of these feathers,” he said. “If you can get these things to build themselves, taking the painstaking process out, then you’d barely have to put any energy and time into it. It would be really cool to see which parameters the birds are changing to get these feathers to self-assemble.”
(WIRED.COM)
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