This paper presents an analysis of the cavity length modulation of a Z-cut quartz etalon equipped with a weight for Laser Diode (LD) wavelength lockers. The electro-optic effect, piezoelectric effect and photo-elastic effect are considered, and the mechanical movement of the etalon with a weight is analyzed by using a mechanical circuit. Approximate equations that clearly explain the mechanical force, mechanical resonance frequency, and Q factor of the mechanical resonance are obtained. The mechanism for improving the modulation efficiency by placing a weight is clarified. We also compare the analysis with experimental results, and show that most of the experimental values are in accord with the calculated values.

This paper presents a wavelength lock system using a Z-cut quartz etalon supported at the middle point. The Z-cut quartz etalon possesses the cavity length modulation and the low temperature coefficient. We propose a Z-cut quartz etalon supported at the middle point in order to improve the modulation index and response time. The mechanism of the center supported Z-cut quartz etalon is described. We also show that the etalon possesses a high modulation index, a high Q factor, and a rapid response time in experimental results. A self-tuning dither oscillator realized by using quartz etalon is also described.

Intensity-noise characteristics of stable multi-mode Fabry-Perot semiconductor lasers are analyzed experimentally and theoretically. Mode-partition noise caused by optical filtering and propagation through optical fibers is investigated by evaluating the relative intensity noise and signal-to-noise ratio. The experimental results indicate that the simplified two-mode analysis provides a good approximation. Suppression of the mode-partition noise by nonlinear gain is experimentally confirmed.