WAVELENGTH LOCKER, WAVELENGTH VARIABLE LASER DEVICE EMPLOYING THE SAME, AND CONTROL METHOD FOR WAVELENGTH VARIABLE LASER DEVICE

摘要

To provide a technology capable of independently performing wavelength control and temperature control by detecting deviation of a light source wavelength and temperature deviation of a wavelength filter by a simple method.SOLUTION: A wavelength locker comprises: means for branching a part of an output light from a light source into first monitor light and second monitor light; a first periodic filter to which the first monitor light is inputted; a second periodic filter to which the second monitor light is inputted; a first light-receiving element for monitoring an intensity of the light transmitted through the first periodic filter; and a second light-receiving element for monitoring an intensity of the light transmitted through the second periodic filter. The first periodic filter and the second periodic filter have such a wavelength property that the intensity of the transmitted light is periodically changed with respect to a wavelength. For the first periodic filter and the second periodic filter, shift directions of a wavelength property with respect to a temperature change are reverse to each other.SELECTED DRAWING: Figure 1