Abstract

Frequency stabilized lasers have been used in many fields, such as high-resolution spectroscopy, harmonic generation using external cavities, and laser interferometers for gravitational wave detection. For the gravitational wave detection, laser FM noise of less than $3\times {10}^{-7}\text{Hz}/\sqrt{\text{HZ}}$ is required as relative stability. In frequency stabilization, FM noise is limited in principle by shot noise at a photodetector used for the stabilization. To reach the FM noise, the utilized power will become more than 100 W at a photodetector. As the acceptable power of a single photodiode is limited to approximately 10 mW, if more than 10 mW will be used, the power will have to be divided to several photodiodes. Until now, there is no report to our knowledge as for frequency stabilization using multi-photodiodes. The power divided photodetector using multi-photodiodes is essential technique for the gravitational wave detection.

© 1994 Optical Society of America