Patent ID: 8735802
Filing Date: 2014-05-27
Classification: H01S,H04B

Abstract:
1. An optical transmission device, comprising: an optical transmission unit which includes a light source that emits a laser beam, a modulator that modulates the laser beam, a modulator temperature detection element that detects a modulator temperature of the modulator, and a temperature control element that has functions of heating and cooling the modulator to execute a temperature control; a main control unit that controls actions of each section of the optical transmission unit; a memory unit that records table information generated in advance for setting a bias voltage for the modulator; a casing that houses the optical transmission unit, the main control unit, and the memory unit; and a casing temperature detection element that detects a casing temperature of the casing, wherein the main control unit includes: a function which functions when the casing temperature is within a range of a low-temperature side reference temperature and a high-temperature side reference temperature set in advance so as to stop each control action regarding heating and cooling of the temperature control element for the modulator; a function which functions when the casing temperature is equal to or lower than the low-temperature side reference temperature so as to execute a heating control of the temperature control element and to set the bias voltage corresponding to the low-temperature side reference temperature to the modulator based on the table information; and a function which functions when the casing temperature is equal to or higher than the high-temperature side reference temperature so as to execute a cooling control of the temperature control element and to set the bias voltage corresponding to the high-temperature side reference temperature to the modulator based on the table information.