{"id":78114,"date":"2020-09-29T22:22:23","date_gmt":"2020-09-29T19:22:23","guid":{"rendered":"https:\/\/en.buradabiliyorum.com\/microcomb-injected-pulsed-lasers-as-variable-microwave-gears\/"},"modified":"2020-09-29T22:22:23","modified_gmt":"2020-09-29T19:22:23","slug":"microcomb-injected-pulsed-lasers-as-variable-microwave-gears","status":"publish","type":"post","link":"https:\/\/buradabiliyorum.com\/en\/microcomb-injected-pulsed-lasers-as-variable-microwave-gears\/","title":{"rendered":"#Microcomb-injected, pulsed lasers as variable microwave gears"},"content":{"rendered":"

“#Microcomb-injected, pulsed lasers as variable microwave gears<\/strong>”<\/p>\n

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\"Microcomb-injected,
\n Injected by a microresonator frequency comb, a high-speed-modulated semiconductor laser can simultaneously generate low-noise microwaves and frequency combs with variable frequency gaps. Credit: Ecole Polytechnique Federale de Lausanne (EPFL)
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Low-noise microwave signals are of critical importance in numerous app<\/a>lications such as high-speed telecommunication and ultrafast data processing. Conventionally, such signals are generated with bulky and delicate microwave oscillators that are not suitable for out-of-door applications. But recently, physicists have been exploring a possible alternative: high-quality microwave generation using optical microresonator frequency combs.<\/p>\n


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Relying on the high optical frequency and spectral purity of laser fields, optical microresonators can generate low-noise microwaves in a compact and efficient manner. But a microresonator can usually only generate microwaves with very limited frequency tunability. The reason is that the microwave frequency depends on the resonator’s size, which is not itself highly tunable.<\/p>\n

Publishing in Science<\/a> Advances<\/i>, researchers at Tobias Kippenberg’s lab at EPFL, Trinity College Dublin (TCD), and Dublin City University (DCU) have now developed a novel technique for generating variable low-noise microwaves with a single optical microresonator.<\/p>\n

The approach injects a microresonator frequency comb into a compact laser whose intensity is modulated by an off-the-shelf microwave oscillator. By forcing the modulation frequency to tightly follow a subharmonic frequency of the microwave produced by the microresonator frequency comb, the team successfully generated new microwaves whose frequencies can be varied significantly.<\/p>\n

In addition, the newly generated microwaves show much lower phase-noise levels than those of a microresonator frequency comb oscillator and off-the-shelf microwave oscillators. This mechanism, called frequency division, is used to transfer the frequency purity of an optical signal into the microwave domain.<\/p>\n

The developed technique enables the spectral purity transfer between different microwave signals. “Traditionally, executing perfect microwave frequency division in a variable fashion has not been easy,” explains Dr. Wenle Weng, who led the study. “Thanks to the fast-modulated semiconductor laser developed by our colleagues at TCD and DCU, now we can achieve this using a low-cost photodetector and a moderate control system.” The semiconductor laser also generates a secondary frequency comb with more densified spectral emissions that can be useful in many spectroscopic applications.<\/p>\n

The key components in the setup of the proof-of-concept experiment, including the microresonator and the semiconductor laser, are discrete and connected with lengthy fibers. The team is now working on integrating and advanced-packing the device. With the ability to be miniaturized and mass-produced, a variable microwave oscillator and frequency comb generator like that can revolutionize the current surging market for portable low-noise microwave and frequency comb sources.<\/p>\n\n

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Photonic microwave generation using on-chip optical frequency combs\n <\/p><\/div>\n

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\n More information:<\/strong>
\n Wenle Weng et al. Frequency division using a soliton-injected semiconductor gain-switched frequency comb, Science Advances<\/i> (2020). DOI: 10.1126\/sciadv.aba2807<\/a><\/p><\/div>\n
\n Provided by
\n Ecole Polytechnique Federale de Lausanne
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Citation<\/strong>:
\n Microcomb-injected, pulsed lasers as variable microwave gears (2020, September 29)
\n retrieved 29 September 2020
\n from https:\/\/phys.org\/news<\/a>\/2020-09-microcomb-injected-pulsed-lasers-variable-microwave.html<\/p>\n

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\n part may be reproduced without the written permission. The content is provided for information purposes only.<\/p><\/div>\n<\/p><\/div>\n