Nakagawa M, Kanda N, Otsu T, Ito I, Kobayashi Y, Matsunaga R. Jitter correction for asynchronous optical sampling terahertz spectroscopy using free-running pulsed lasers.
OPTICS EXPRESS 2023;
31:19371-19381. [PMID:
37381353 DOI:
10.1364/oe.488866]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Accepted: 05/16/2023] [Indexed: 06/30/2023]
Abstract
We demonstrate a jitter correction method for asynchronous optical sampling (ASOPS) terahertz (THz) time-domain spectroscopy using two free-running oscillators. This method simultaneously records the THz waveform and a harmonic of the laser repetition rate difference, Δ f r, to monitor the jitter information for software jitter correction. By suppressing the residual jitter below 0.1 ps, the accumulation of the THz waveform is achieved without losing the measurement bandwidth. Our measurement of water vapor successfully resolves the absorption linewidths below 1 GHz, demonstrating a robust ASOPS with a flexible, simple, and compact setup without any feedback control or additional continuous-wave THz source.
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