Beijing on October 11, 1962, 50 years ago, Nick Ho Lun Yake (Nick Holonyak Jr.) And its team of General Electric invented the light-emitting diode (Light Emitting Diode, LED). Today LED light has been almost everywhere - from the bridge to the headlights and then keychain flashlight, LED light looks brighter than the sun - but its initial development is full of uncertainty research and compete with each other. At the time, the LED is another pioneering technology - laser - a direct result, in the days that followed, LED has been in the further evolution of lighting source has now become our home, was also used to transmit our data.
"Connection" magazine design channel now for the University of Illinois Professor Ho Lun Yake interview, asked him about the history of the LED, also discussed the future of the LED. The following is a summary of the contents of this interview:
"Connection: LED is first taken out of the market reaction is what?
He Lun Yake: when I recognize themselves when walking in the development of the LED on the road, I've used the alloy to produce their own visible laser field to defeat the entire world. An editor of the "Reader's Digest" (Reader's Digest) in February 1963 gave me the phone, and pointed out a fact is that LED will eventually cover the entire spectrum of white light sources. That is what happened at the time, but I think the time this happened like far so long as 50 years.
He Lun Yake: There were a lot of speculation that the light may not be able to have coherence, like a microwave signal; or, if energy coherence of the human eye may not see, because of this the human eye has been can only see the non-coherent light.
While other people think Ruby can not become a light source, but a scientist named Theodore · Maiman (Theodore Maiman) was an idea that ruby can be used as a maser, but no one have used ruby laser produced. He ultimately successful, I think it should be in May 1960, when he demonstrated how a laser beam is generated. He demonstrated the first laser beam, everything began to break free of the confinement.
In 1962, Robert Redick (Robert Rediker) under the leadership of the Massachusetts Institute of Technology Lincoln Laboratory (Lincoln Laboratories), said they have created a launch many self-emitting diodes, and can use this diode to launch IR i-line signal. When the meeting held in July of that year, they released a report about this diode, many of us say, whether it is possible to become coherent light, for example, a laser?
"Connection": What is the difference between this and Maiman've already done?
Ho Lun Yake: Maiman's laser, it is a kind of similar to the use of flash photography. You can release a bunch of strong white light beam then white ruby rod, the ruby rod then all red chromium atoms are promoted to a higher state, and then released, it becomes a laser beam. It is a primary process to promote the program of the secondary process. All the light you see is heat, and heat make atoms vibrate gently, to release some kind of light. It is not so much the illuminator, rather heater better.
Of said laser is from one end into and then out of the light from the other end, in that the distance of its own is the light generator, that is, diode laser.
"Connection": the first LED?
Ho Lun Yake: Very small. Of course, you may be allowed to become larger, and it has also been doing. You know, in the field of semiconductor applications, the semiconductor will always win, swept the ordinary electronic products.
"Connection": the time LED looks today much like you?
Ho Lun Yake: LED you see today is at a low cost platform, but that is only a formality. In fact, LED can be produced in various forms, the varieties and geometries can be different.
Connection: What can we do?
He Lun Yake: a lot of things can be done to let it become more appropriate. We are still looking for better ways to manufacture crystal chemical research, so that everything is in its place.
General Electric produced the first piece of alloy. Then I made some other semiconductor alloys, they get better - that is, you can now see the alloy, they can emit red-orange light, and then the yellow light. Then, other people to switch to other forms of alloy, allowing it to emit blue light; converted to blue green, they encounter greater difficulties. Moreover, no one can very well solve the problem to obtain yellow.
"Connection": After these developments, LED has become the mainstream use of the light source.
He Lun Yake: As a whole, LED is beginning to take over the lighting market, are so special lighting to all types of lighting. For now, the whole world is in the use of forms and different colors of LED.
Connection: Well, we will see the use of LEDs continues to grow?
He Lun Yake: you can only LED as a light source, but can also be allowed to appear in the form of laser used in the field of surgery and photosensitizing, and you can not do the same thing with a light bulb. That is like saying, I have to put a vacuum tube made of pacemaker on a patient's body - it can only be a joke.
You can use the LED to produce a series of things, whether it is in the field of medicine, equipment or car. Some car companies have done all the lights on the car are light-emitting diodes, which makes both headlights, tail lights or indicator without replacement, because the LED lights lasting use.
This is not the end, in fact, to some extent, LED is in infancy. Although from time the LED long past infancy but my feeling is that the future it still have to walk a very, very long way, for that matter is still in the infant midterm.
"Connection": you are still engaged in this work?
Ho Lun Yake: No, I and my partners have other things to do. A particle flow in the transistor was originally useless, but also has become a light emitter laser signal, so now we have two forms of signal can become part of the new generation of chips .
The better the propagation of the optical information in the electronic information. Electron will lose power in the process of transfer from one place to another place, the optical signal will have to be much better. Optical signal can be used to make a chip, but it is 10 years, 20 years, 30 years or even 40 years of unremitting efforts to do things.