Continuous adiabatic frequency conversion for FMCW-LiDAR.

Continuous tuning of the frequency of laser light serves as the fundamental basis for a myriad of applications spanning basic scientific research to industrial settings. These applications encompass endeavors such as the detection of gravitational waves, the development of precise optical clocks, environmental monitoring for health and ecological purposes, as well as distance measurement techniques. However, achieving a broad tuning range exceeding 100 GHz along with sub-microsecond tuning times, inherent linearity in tuning, and coherence lengths beyond 10 m presents significant challenges.

Mid-infrared frequency combs and staggered spectral patterns in χ microresonators.

The potential of frequency comb spectroscopy has aroused great interest in generating mid-infrared frequency combs in the integrated photonic setting. However, despite remarkable progress in microresonators and quantum cascade lasers, the availability of suitable mid-IR comb sources remains scarce. Here, we generate mid-IR microcombs relying on cascaded three-wave-mixing for the first time.

Pump tuning of a mid-infrared whispering gallery optical parametric oscillator.

Optical parametric oscillators (OPOs) constitute an important coherent, narrow-linewidth and widely tunable light source with applications in spectroscopy and many other fields. Their realizations based on whispering gallery resonators (WGRs) provide a small footprint and ultra-low thresholds, with demonstrations of tunability typically done via temperature variation. In this work, we show the pump tuning capabilities of a mm-sized WGR mid-infrared OPO made of CdSiP.

Soliton based χ combs in high-Q optical microresonators.

Investigations of the frequency combs in χ microresonators have passed a critical point when the soliton based regimes are well established and realized on different platforms. For χ microresonators, where the first harmonic (FH) and second harmonic (SH) envelopes are coupled via the SH generation and optical parametric oscillation, the comb-soliton studies are just starting. Here we report on a vast accessible dual χ soliton-comb family in high-Q microresonators with the SH and FH combs centered at the pump frequency ω and its half ω/2.