Abstract: With a wavelength conversion device based on a nonlinear optical effect, when arrayed waveguides including an intended nonlinear waveguide are fabricated, unwanted slab waveguides are inevitably formed. The slab waveguides can cause an erroneous measurement in the selection of a waveguide having desired characteristics from the arrayed waveguides. The erroneous measurement can lead to redoing steps for fabricating the wavelength conversion device and a decrease in the yield and inhibit the evaluation of the characteristics in selection of the waveguide and the subsequent fabrication of the wavelength conversion device from being efficiently performed. A wavelength conversion device according to the present invention includes a plurality of waveguides formed on a substrate, and a plurality of slab waveguides that are arranged substantially in parallel with and spaced apart from the plurality of waveguides, and a guided light attenuator is formed in each of the slab waveguides.

Abstract: There is provided an optical element mounted on a substrate and an optical coupling element mounted on the substrate. The optical coupling element includes a guide unit extending in a direction parallel to a plane of the substrate so as to fix an optical fiber. There is provided a mold resin layer formed on the substrate so as to cover the optical element and expose a side surface of the optical coupling element at one end of the guide unit. The optical element includes a light incidence/emission unit on a side surface perpendicular to the plane of the substrate, and the other end of the guide unit and the light incidence/emission unit are disposed to face each other.

Abstract: An optical circuit is provided in which electric circuit parts and optical circuit parts are integrated in a stack on a printed substrate. The optical circuit is provided with a lid having a temperature regulation function that uses a temperature control element and an optical fiber block capable of optical input and output. Temperature control of optical circuit elements can be efficiently performed by mounting electric circuit parts and optical circuit parts on a printed substrate in advance by a reflow step using OBO technology and subsequently attaching a lid that includes a temperature control element.

Abstract: An optical device includes a waveguide configured with a waveguide core and clad layers. A thickness of the upper clad layer between a surface of a coupling unit of the waveguide and the waveguide core is set to a thickness with which optical evanescent coupling is capable of being performed with a waveguide or optical fiber for monitoring in a case where the waveguide or optical fiber for monitoring is arranged in a vicinity of the surface of the coupling unit.

Abstract: An optical module includes: a substrate; one or more light sources that produce light that is an optical signal; one or more light reflection units that change the direction of travel of the light to a direction substantially perpendicular to the substrate; one or more optical waveguides that optically connect the one or more light sources and the one or more light reflection units to each other; and a lid that is attached to the substrate to cover the one or more light sources, the one or more light reflection units and the one or more optical waveguides. The lid has one or more lenses that collimate light directed by the one or more light reflection units and transmit the light to the outside of the lid.

Abstract: The present invention provides a configuration of a novel optical transmitter which outputs stable PDM signals. The novel optical transmitter generates phase conjugate light using a single second-order non-linear optical element included in a phase conjugate light generator with a looped configuration. A relative phase of main signal light with respect to excitation light and phase conjugate light of the main signal light stabilizes between two polarized components, and a PDM signal including a pair of a polarization-multiplexed signal and phase conjugate light in a stable phase state can be generated and transmitted. The present invention can provide an optical transmitter that generates a PDM signal in which a variation in a phase between quadrature polarized waves is suppressed. By stabilizing quality of a PDM transmission signal on a side of the optical transmitter, a phase sensitive amplifier in a polarization diversity configuration can be operated in a stable manner.