![]() ![]() The laser produces optical pulses at a microwave rate, and each pulse is directed through a microchip waveguide structure to generate many more colors in the frequency comb. To make the electro-optic laser, NIST researchers start with an infrared continuous-wave laser and create pulses with an oscillator stabilized by the cavity, which provides the equivalent of a memory to ensure all the pulses are identical. So, hyperspectral imaging that currently takes a minute could happen in real time." Using our technology, this kind of imaging could happen dramatically faster. "Probing biological samples with ultrafast pulses provides both imaging and chemical makeup information. "Chemical and biological imaging is a good example of the applications for this type of laser," Papp said. ![]() So that's the speedup here - ultrafast pulses that arrive 100 times faster or more." In our electro-optic laser, the pulses come out every 100 picoseconds. "In mode-locked lasers, the pulses come out every 10 nanoseconds. "In any ultrafast laser, each pulse lasts for, say, 20 femtoseconds," lead author David Carlson said. In contrast, NIST's new electro-optic laser imposes microwave electronic vibrations on a continuouswave laser operating at optical frequencies, effectively carving pulses into the light. Interoperation of optical and microwave signals powers the latest advances in communications, timekeeping and quantum sensing systems. Combs are usually made with sophisticated "mode-locked" lasers, which form pulses from many different colors of light waves that overlap, creating links between optical and microwave frequencies. The conventional source of ultrafast light is an optical frequency comb, a precise "ruler" for light. This is faster than the nanoscale regime, introduced to the cultural lexicon some years ago with the field of nanotechnology (nanoseconds are billionths of a second). Ultrafast refers to events lasting picoseconds (trillionths of a second) to femtoseconds (quadrillionths of a second). As the signals bounce back and forth inside something like a soda can, fixed waves emerge at the strongest frequencies and block or filter out other frequencies. "We tamed the light with an aluminum can," project leader Scott Papp said, referring to the "cavity" in which the electronic signals are stabilized and filtered. 28 issue of Science, NIST scientists developed a filtering method to reduce the heatinduced interference that otherwise would ruin the consistency of electronically synthesized light. But until now researchers have been unable to electronically switch light to make ultrafast pulses and eliminate electronic noise, or interference.Īs described in the Sept. The technology for making electrooptic lasers has been around for five decades, and the idea seems alluringly simple. ![]()
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