The invention discloses a method and device for preventing
wavelength of an emitted light from being fluctuated during power-up of an
optical module. When the
optical module is powered up, a controller only sends a first turn-on instruction to a TEC
control circuit, so as to control a TEC to be turned on. The controller determines
delay time according to a
temperature difference between temperature of an emitting
laser and a target temperature value and sends a second turn-on instruction to the emitting
laser when turn-on wait time of the emitting
laser reaches the
delay time, so as to controlthe emitting laser to be turned on. At the moment, temperature of the emitting laser when starting to emit light is almost close to or equal to the target temperature value, temperature change is small,
wavelength of the light can not be fluctuated or produced fluctuation is relatively small, then the laser can be protected from being interfered by temperature fluctuation, and laser can be emitted as quickly as possible. Therefore, the method and device which are provided by the invention not only can avoid light
wavelength fluctuation phenomenon and protect the emitting laser but also can enable the
optical module to output light with stable wavelength as quickly as possible, and standards of the optical module are met.