Abstract

A Fabry-Perot wavemeter for analyzing pulsed laser sources used in a coherent anti-Stokes Raman spectrometer is constructed with an array detector. This wavemeter allows the real-time measurement of both the wavelength and the spectral purity of the laser pulse produced at 10 Hz. The performance of the wavemeter is checked with a frequency stabilized He-Ne laser and a doubled Nd:YAG laser, which is operated in a single-longitudinal mode by injection locking with a cw laser. Measuring the spectral purity of the pulses of the doubled YAG laser, we can improve the quality of the spectroscopic data by eliminating the signal generated by the bad pulse which is not completely locked. The resolution of the wavemeter is found to be >10 MHz. Also, we have calculated the errors in determining the wave-number by processing a Fabry-Perot fringe pattern imaged on a linear array detector. The calculation is done by changing the finesse of the Fabry-Perot etalon, the number of pixels of the array detector, the magnitude of random noise, the beam waist of the input laser beam, etc.

© 1991 Optical Society of America