Patent ID: 11971644
Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A wavelength conversion device that generates light different in wavelength from a signal light when the signal light is inputted, comprising:
a wavelength conversion element that converts a wavelength of the signal light; and
a temperature control element for controlling a temperature of the wavelength conversion element, wherein
the wavelength conversion element and the temperature control element are sealed in an inside of a metal casing, and the inside of the metal casing is filled with dry gas including one or more selected from nitrogen, oxygen, argon or helium,
the wavelength conversion element includes an optical waveguide core and a substrate having a lower refractive index to the signal light than the optical waveguide core, and
the substrate is a ferroelectric substance in which directions of spontaneous polarization are random.