Microresonator soliton dual comb spectroscopy
Shrinking spectrometers Dual comb spectroscopy is a powerful technique that uses the interference of two closely related combs to map spectroscopic features directly into a frequency domain that can be read by electronics. Suh et al. developed a dual comb spectroscopy approach using combs produced by silica microresonators fabricated on a silicon chip. Perhaps high resolution spectroscopy will soon be shrunk to the chip scale, doing away with the need for bulky spectrometers. Science, this issue p. 600 Dual comb spectroscopy is demonstrated using a pair of silica microresonators. Measurement of optical and vibrational spectra with high resolution provides a way to identify chemical species in cluttered environments and is of general importance in many fields. Dual comb spectroscopy has emerged as a powerful approach for acquiring nearly instantaneous Raman and optical spectra with unprecedented resolution. Spectra are generated directly in the electrical domain, without the need for bulky mechanical spectrometers. We demonstrate a miniature soliton based dual comb system that can potentially transfer the approach to a chip platform. These devices achieve high coherence pulsed mode locking. They also feature broad, reproducible spectral envelopes, an essential feature for dual comb spectroscopy. Our work shows the potential for integrated spectroscopy with high signal to noise ratios and fast acquisition rates.
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