Chip based comb laser illumination and unlocking of new applications

Researchers have shown that dissipative Kerr solitons (DKS) can be used to create chip based optical frequency combs with sufficient output power for optical atomic clocks and other practical applications. This progress may lead to chip based instruments being able to perform precise measurements that were previously only possible in a few specialized laboratories.

Gr é gory Moille from the NIST/University of Maryland Joint Quantum Research Institute will showcase this research area at the Optics+Laser Science Frontiers (FiO LS) conference center in Tacoma (Greater Seattle) from October 9-12, 2023, Washington.

Frequency combs are ubiquitous in metrology - just like rulers measuring length, they allow us to measure the frequency of light very accurately, "Moir said. Making them on a chip helps us greatly reduce power consumption, but also reduces the power of each comb. This makes it difficult for on chip combs to connect to other systems such as atomic frequency standards. We have demonstrated that by simply and carefully injecting laser into another weak comb device, it enables us to adjust the system and optimize the power of multiple comb teeth by more than an order of magnitude

The optical frequency comb emits a series of continuous short and closely spaced light pulses, containing millions of colors, which can be used to measure light waves, just like measuring radio waves. This enables technologies such as atomic clocks, computers, and communication to be connected to light waves, whose oscillation frequency is 10000 times higher than that in electronic products.

Although traditional optical frequency combs are generated using mode-locked lasers, which are often limited to high-end scientific laboratories, there has been recent work using compact chip level microresonators based on DKS to develop optical frequency combs. DKS is an optical packet that relies on a dual balance of nonlinearity and dispersion, as well as dissipation and gain. Although DKS based optical combs consume very little energy, they cannot generate enough output power to function effectively.

In this new work, researchers utilize the newly proposed Kerr induced Kerr soliton synchronization and external stable laser reference to generate optical frequency combs with higher power levels. This significantly increases the power on the other side of the reference laser comb spectrum.

Researchers have theoretically and experimentally demonstrated that the external reference pump of 193 THz can adjust the repetition rate of the octave comb. This allows for adjusting the phase matching conditions of the comb teeth at the dispersion wave in a way that optimizes its power. In addition to the self balancing effect directly related to the robustness of the DKS core, their power has increased by more than 15 times at 388 THz comb teeth.

We just touched the surface of optimizations that can be executed, "Moyle explained. We have not yet reached this optimized power limit and hope to achieve a power level that is compatible with our comb directly connecting to other systems

On the Frontiers of Optics and Laser Science
The Optica (formerly known as OSA) annual conference "Optical Frontiers" is held in conjunction with the annual conference "Laser Science" of the Laser Science Division of the American Physical Society. These two conferences unite the communities of the two societies to conduct comprehensive and up-to-date research on the themes of optics and photonics, as well as various fields of physics, biology, and chemistry. The 2023 FiO LS conference will be held in the form of on-site events, including hundreds of on-site contributions and invited speeches, as well as other on-demand content available for online viewing. Media registration is free with a certificate. Digital assets can be provided upon request.

About Opka
Optica (formerly OSA), also known as the Society for the Advancement of Global Optics and Photonics, is an association dedicated to promoting the generation, application, archiving, and dissemination of knowledge in this field. It was founded in 1916 and is a leading organization for scientists, engineers, business professionals, students, and others interested in optical science. Optica's renowned publications, conferences, online resources, and on-site activities promote discovery, shape real-world applications, and accelerate scientific, technological, and educational achievements.

Source: Laser Network