Reference-free dual-comb spectroscopy with inbuilt coherence: publisher's note.

This publisher's note contains a correction to Opt. Lett.49, 2473 (2024)10.

Reference-free dual-comb spectroscopy with inbuilt coherence.

We demonstrate a simple system for dual-comb spectroscopy based on two inherently coherent optical frequency combs generated via seeded parametric downconversion. The inbuilt coherence is established by making the two combs share a common comb line. We show that the inbuilt coherence makes it possible to use a simple numerical post-processing procedure to compensate for small drifts of the dual-comb interferogram arrival time and phase.

Versatile optical frequency combs based on multi-seeded femtosecond optical parametric generation.

This study proposes and demonstrates a versatile method for near- and mid-infrared optical frequency comb generation using multi-seeded femtosecond optical parametric generation. The method allows one to divide the repetition rate by an arbitrarily large integer factor, freely tune the offset frequency, and adjust the common phase offset of the comb modes. Since all possible degrees of freedom are adjustable, the proposed method manifests itself as versatile optical frequency synthesis.

Mid-infrared frequency comb with 25 pJ threshold via CW-seeded optical parametric generation in nonlinear waveguide.

We demonstrate efficient generation of mid-infrared frequency combs based on continuous-wave-seeded femtosecond optical parametric generation in nonlinear waveguides. Conversion of the near-infrared pump to signal and idler light takes place with very high efficiency (74%), and the threshold (25 pJ for 100 fs pulses) is over 300 times lower than in bulk analogs. Relative intensity noise of the mid-infrared comb is exceptionally low, below 5×10 (integrated from 10 Hz to 2 MHz).