Wavelength converter

A wavelength converter configured to generate light with a wavelength different from a wavelength of a signal light when the signal light is input, the wavelength converter comprising:

• a wavelength conversion element including a substrate as a base with a light waveguide core at a first main surface, the substrate having a lower refractive index for the signal light than the light waveguide core, the wavelength conversion element being configured to convert the wavelength of the signal light;
• a temperature control element joined to a portion excluding both of one end portion and another end portion in a second main surface of the substrate, and configured to support the wavelength conversion element and control a temperature of the wavelength conversion element;
• a support structure configured to support the wavelength conversion element through a contact at a tip end surface at a position corresponding to at least one end portion of the light waveguide core in the second main surface of the substrate at occurrence of elastic deformation due to a thermal stress during wavelength conversion of the wavelength conversion element;
• and
• a metal housing bottom surface member disposed at a bottom surface inside a metal housing configured to house the wavelength conversion element, the metal housing bottom surface member being a member where the support structure is provided,
• wherein the support structure is provided at a portion apart from the temperature control element at a top surface of the metal housing bottom surface member, and the tip end surface is disposed in a vicinity of the position in the second main surface of the substrate,
• wherein the support structure includes a temperature control mechanism configured to perform a temperature control of the wavelength conversion element from a side of the second main surface of the substrate.