Uni-Quanta
飽和吸収分光検出システム
(Saturated Absorption Spectra Detecting System）

システムの紹介（System Introduction）
このシステムはUQEL100分離式半導体レーザーを基礎としての飽和と吸収分光を検出する考案である。それはUQEL100分離式半導体レーザー、光のアイソレーター、飽和と吸収光路、低ノイズ光、電検出器の四つ主な部分で構成する。このシステムでドップラー固有周波数信号を取れること且つお客様要望によりドップラー固有周波数信号を削除することも出来る。このシステムを冷原子物理、レーザー分光、レーザーの周波数安定性、量子のInformation、計測、環境のMonitor、工業の測量などに適用する。
主な仕様(Specifications)：

適用波長（wavelength）	375, 400, 635, 655, 675, 685, 780, 790, 810, 850, 895, 935, 1060, 1260, 1310, 1380, 1450, 1550, 1630, 1700,.nm etc
応用できる出力（Output power on Line)	>10mW
標本化材質(Sampling Material)	Rb, Rb, Cs, Li, Ca, I2, CH4, CO
光アイソレ-ター(Optical isolation ratio)	>50dB
分光パワー(Light Power for Spectra)	<0.5mW
SN比(Signal to Noise Ratio)	>30dB
システム寸法(System Size)	600mm x 360mm x 180mm
稼動温度（Operating temperature）	15~35°C

（Schematic diagram of Saturated Absorption Spectra Detecting System）

System Introduction

The system is a solution to saturated absorption spectra detecting, based on external cavity diode laser UQEL100. It consists of four main parts: external cavity diode laser UQEL100, optical isolator, light path for saturated absorption spectra and low noise photo detector. The system works as the following: The probing light and the re-pumping beam counter-propagate into the sampling cell, and overlap in space. While the frequency of diode laser is scanned to resonant on the transition frequency of the sampling material, the pumping light will pump the sampling material to the excited states and the probing light will pass the excited material with less absorption, which is detected by the photo detector showing transmission peaks on the Doppler absorption background. Generally, the spectra from alkali metals shows six transmission peaks, three of which are resonant lines and others are crossover lines. According to the demands of customers, spectra with or without Doppler background can be both obtained. The system can be utilized in such diverse applications as cold atom physics[1], laser spectroscopy[2], laser frequency stabilization[3], quantum information, metrology, environmental monitor and industrial measurement etc.

Frequency beat signal of two UQEL100 lasers	Saturated absorption spectrum of 87Rb

[1] Lin Xia, Xu Xu, Rui Guo, Fan Yang, Wei Xiong, Juntao Li, Qianli Ma, Xiaoji Zhou, Hong Guo, and Xuzong Chen, Phys. Rev. A 77, 043622 (2008)
[2] Yimin Li, Xuzong Chen, Jianhua Gan, Wangxi Ji, Jingshan Hua, Donghai Yang, Yiqiu Wang，Chin.Phys.Lett., Vol.13,No.6,424(1996)
[3] X.Z. Chen, K. Zhang, J. Zang, Y. Akimoto, T. Kasahara, K. Sakamoto, H. Inaba, Proceedings of SPIE, Vol 3547, 194-202 (1998)