Since the laser frequency-to-current response is non-linear, a closed-loop feed-back system is designed to improve the tuning linearity, and consequently the measurement resolution. For fast active control, an embedded system with FPGA is used, resulting in a nearly linear frequency tuning, ...
The line shape of power spectrum of frequency-modulated laser with delayed self-heterodyne method is presented.Theoretical analysis is carried out and a mathematical expression is used to describe the line shape.According to the theoretical results,the line shape of frequency-modulated laser measured ...
6) tunable laser spectroscopy 可调谐激光光谱 1. When we detect gas concentration by the technology oftunable laser spectroscopy,under the condition of high gas concentration and long gas absorption path,we can use simple linear relation as the approximation of the exponential relation of Lambert-Beer...
Curves are presented showing the fundamental, second-order harmonic and third-order harmonic FM responses. It is found that systems using a frequency-modulated laser and an interferometer would exhibit lower distortion levels than those using direct intensity modulation of the laser diode....
We report on the frequency-modulated operation of a Ti:Al 2 O 3 laser using an intracavity phase modulator. Results are presented for the laser operating in both the frequency-modulated region as well as the mode-locked region, where pulses as short as 12 ps have been generated. This frequ...
Tunable Diode-Laser Absorption Spectroscopy (TDLAS) is increasingly being used to measure trace-gas concentrations down to low part-per-billion levels (1 ppbv = 10 9 volume mixing ratio). Semiconductor lead-salt diode lasers give access to the mid-infrared spectral region and the application of ...
Using heterodyne detection and digital signal processing techniques, incoherent ASE recirculation and laser oscillation in terms of these modes are experimentally verified in a frequency-shifted feedback fiber laser and in a frequency-modulated fiber laser, respectively. The different modal regimes ...
The method for measuring nanovibration amplitudes using the autodyne signal of a semiconductor laser at several laser radiation wavelengths is described. The theoretical description of the frequency-modulated autodyne signal under harmonic vibrations of the reflector is presented and the relations for its ...
Millimetre-wave signal generation by optical filtering of frequency modulated laser spectra 喜欢 0 阅读量: 20 作者:P.A.,Davies,K.E.,Razavi,A.P.,Foord 摘要: We have demonstrated the generation of a 19.2 GHz signal from a 3.2 GHz drive signal; a multiplication factor of 6. This was ...
Lightwave CATV systems using frequency-modulated laser and interferometer The feasibility of using a frequency-modulated laser followed by an interferometer in a subcarrier multiplexed system is considered. It is found that a Fab... SL Woodward - 《Electronics Letters》 被引量: 50发表: 1989年 ...