Stimulated polariton scattering in an intracavity RbTiOPO4 crystal generating frequency-tunable THz output.

Tiago A Ortega,Andrew J Lee,Helen M Pask,David J Spence

doi:10.1364/oe.24.010254

Abstract

A high power, frequency-tunable THz source based on intracavity stimulated polariton scattering (SPS) in RbTiOPO4 (RTP) is demonstrated for the first time. Frequency tunable THz output was obtained from 3.10 to 4.15 THz, with a gap at 3.17 to 3.49 THz, arising from the 104 cm-1 A1 mode in RTP. A maximum average output power of 16.2 µW was detected at 3.8 THz. This is the highest average output power ever reported for an intracavity polariton laser.

Highlights

Spectroscopy and spectral imaging utilizing THz radiation have successfully demonstrated the potential to address a wide variety of revolutionary applications in industry, homeland security and medical sciences [1,2]
Development of reliable, robust and cost-effective THz sources with narrow band and frequency tunable output which can be interfaced with conventional THz detectors is imperative, and the approach considered here uses a conventional diode-pumped Nd laser to produce such frequency-tunable THz radiation via stimulated polariton scattering (SPS) in nonlinear optical crystals [9]
With a desire to produce compact, efficient and diode-pumped THz sources that generate THz output beyond what is achieved with Mg:LiNbO3, in this work we report a frequencytunable THz source based on intracavity SPS in an RTP crystal

Summary

Introduction

Spectroscopy and spectral imaging utilizing THz radiation have successfully demonstrated the potential to address a wide variety of revolutionary applications in industry, homeland security and medical sciences [1,2]. Most of the available sources utilize a time-domain THz spectroscopy configuration (TDS-THz), in which a femtosecond laser pulse irradiates a photoconductive antenna, emitting a very short, broadband THz pulse (typically spanning several terahertz) [2]. These TDS-THz systems rely on high power and expensive laser systems, as well as complex optomechanics and computercontrolled delay lines for detection. Development of reliable, robust and cost-effective THz sources with narrow band and frequency tunable output which can be interfaced with conventional THz detectors is imperative, and the approach considered here uses a conventional diode-pumped Nd laser to produce such frequency-tunable THz radiation via stimulated polariton scattering (SPS) in nonlinear optical crystals [9]

Methods

Results

Conclusion