A DECADE-SPANNING HIGH-RESOLUTION ASYNCHRONOUS OPTICAL SAMPLING BASED TERAHERTZ TIME-DOMAIN SPECTROMETER

Good, Jacob T

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https://hdl.handle.net/2142/79398 Copy

Description

Title

A DECADE-SPANNING HIGH-RESOLUTION ASYNCHRONOUS OPTICAL SAMPLING BASED TERAHERTZ TIME-DOMAIN SPECTROMETER

Author(s)

Good, Jacob T

Contributor(s)

• Blake, Geoffrey
• Allodi, Marco A.
• Carroll, Brandon
• Finneran, Ian
• Holland, Daniel

Issue Date

23-Jun-15

Keyword(s)

Mini-symposium: High-Precision Spectroscopy

Abstract

High-resolution ASynchronous OPtical Sampling (ASOPS) is a technique that substantially improves the combined frequency resolution and bandwidth of ASOPS based TeraHertz Time-Domain Spectroscopy (THz-TDS) systems. We employ two mode-locked femtosecond Ti:Sapphire oscillators with repetition frequencies of 80 MHz operating at a fixed repetition frequency offset of 100 Hz. This offset lock is maintained by a Phase-Locked Loop (PLL) operating at the 60th harmonic of the repetition rate of the Ti:Sapphire oscillators. Their respective time delay is scanned across 12.5 ns requiring a scan time of 10 ms, supporting a time delay resolution of up to 15.6 fs. ASOPS-THz-TDS enables high-resolution spectroscopy that is impossible for a THz-TDS system employing a mechanical delay stage. We measure a timing jitter of 1.36 fs for the system using an air-gap etalon and an optical cross-correlator. We report a Root-Mean-Square deviation of 20.7 MHz and a mean deviation of 14.4 MHz for water absorption lines from 0.5 to 2.7. High-resolution ASOPS-THz-TDS enables high resolution spectroscopy of both gas-phase and condensed-phase samples across a decade of THz bandwidth.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

English

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http://hdl.handle.net/2142/79398

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