WAVELENGTH MONITOR APPARATUS, OPTICAL MODULE, AND OPTICAL MODULE ASSEMBLING METHOD

摘要

A wavelength filter is arranged between a photo diode receiving back-emission light of a laser diode and the laser diode. An incoming surface or an outgoing surface at one end of the wavelength filter is attached to a holding portion of a metal holder, thereby constituting a wavelength monitor apparatus. Thus, it is possible to obtain a holding structure not causing deterioration of optical characteristic of the wavelength filter when the wavelength filter having a doubly refracting crystal is held and fixed or not causing damage of the wavelength filter attributed to a temperature change.