Numerical Study of Compact Terahertz Gas Laser Based on Photonic Crystal Fiber Cavity

Abstract

We report a compact terahertz (THz) gas laser based on the cavity photonic crystal fiber (PCF). This compact structure consists of a large air core PCF constructed by high-density polyethylene tubes. The 2.52 THz wave can be generated in the reaction cell filled with the CH <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> OH gas. The reaction cell should shrink the volume of THz sources. The saturation intensity is analyzed based on the rate equations theory. Numerical calculations show that the THz wave can realize the fundamental mode transmission and obtain a lower confinement loss of 5.6 dB/m and the flat bending loss spectrum. The optimum pressure, pump threshold are analyzed and the THz output power can reach the magnitude of 10 mW. We combined the THz pump technology and the excellent transmission characteristics of the PCF together. This compact THz gas laser gives a new method to realize the THz source with high beam quality, low transmission loss, well-distributed bending shape and small size.