Abstract: A semiconductor light modulator (5) modulates light in accordance with a high-frequency wave signal (11). A terminal matching circuit (12) is connected in parallel to the semiconductor light modulator (5). The terminal matching circuit (12) has a resistor (8) and a capacitor (9) of 0.1 pF or lower connected in parallel to the resistor (8).

Abstract: A problem with a conventional waveguide type laser device is that in the case in which an isotropic laser medium is used for a core, linearly polarized light is not provided. A ridge waveguide laser device of the present disclosure includes: a substrate; a core joined to the substrate and having a laser medium, the core having a refractive index higher than that of the substrate; and a cladding joined to the core, constituting a ridge waveguide together with the core, and made from a birefringent material having ordinary and extraordinary refractive indices lower than the refractive index of the core, the ordinary and extraordinary refractive indices being different.

Abstract: A problem with a conventional waveguide type laser device is that in the case in which an isotropic laser medium is used for a core, linearly polarized light is not provided. A ridge waveguide laser device of the present disclosure includes: a substrate; a core joined to the substrate and having a laser medium, the core having a refractive index higher than that of the substrate; and a cladding joined to the core, constituting a ridge waveguide together with the core, and made from a birefringent material having ordinary and extraordinary refractive indices lower than the refractive index of the core, the ordinary and extraordinary refractive indices being different.

Abstract: In a planar waveguide laser device (1), a substrate (6) is joined to the upper surface of a waveguide (2). A recess (6a) having a chamfered shape is formed along an edge of an end facet of the substrate (6) on the side of the waveguide (2), the end facet being perpendicular to the direction of laser oscillation. An end facet of the waveguide (2) perpendicular to the oscillation direction of laser light is covered with a coating (7). A wraparound portion (7a) continuing from the coating (7) covers the upper surface of the waveguide (2) facing the recess (6a) of the substrate (6).

Abstract: In a planar waveguide laser device (1), a substrate (6) is joined to the upper surface of a waveguide (2). A recess (6a) having a chamfered shape is formed along an edge of an end facet of the substrate (6) on the side of the waveguide (2), the end facet being perpendicular to the direction of laser oscillation. An end facet of the waveguide (2) perpendicular to the oscillation direction of laser light is covered with a coating (7). A wraparound portion (7a) continuing from the coating (7) covers the upper surface of the waveguide (2) facing the recess (6a) of the substrate (6).

Abstract: There are provided: a planar waveguide in which claddings (2) and (3) each having a smaller refractive index than a laser medium for absorbing pump light (5) are bonded to an upper surface (1a) and a lower surface (1b) of a core (1) which is formed from the laser medium; pump light generation sources (4a) and (4b) for emitting pump light (5) to side surfaces (1c) and (1d) of the core (1); and laser light high reflection films (6a) and (6b) formed on side surfaces (1e) and (1f) of the core (1). Each of side surfaces (2e) and (2f) of the cladding (2) corresponding to the side surfaces (1e) and (1f) of the core (1) has a ridge structure (20) in which a part thereof is recessed.

Abstract: There are provided: a planar waveguide in which claddings (2) and (3) each having a smaller refractive index than a laser medium for absorbing pump light (5) are bonded to an upper surface (1a) and a lower surface (1b) of a core (1) which is formed from the laser medium; pump light generation sources (4a) and (4b) for emitting pump light (5) to side surfaces (1c) and (1d) of the core (1); and laser light high reflection films (6a) and (6b) formed on side surfaces (1e) and (1f) of the core (1). Each of side surfaces (2e) and (2f) of the cladding (2) corresponding to the side surfaces (1e) and (1f) of the core (1) has a ridge structure (20) in which a part thereof is recessed.

Abstract: An object is to provide an optical device capable of relaxing a manufacturing condition for an optical waveguide used in the optical device. An optical device 500 is provided with an optical waveguide 200 including a core and a cladding optically joined together, and a temperature controller 600 that controls temperature of the optical waveguide, wherein the optical waveguide includes the core and the cladding formed such that a normalized frequency specified for light propagating through the optical waveguide changes across a cutoff frequency of a guided mode determined from a structure of the optical waveguide in a temperature range in which a refractive index of the core is higher than a refractive index of the clad. The temperature controller controls the temperature of the optical waveguide over a temperature range across temperature at which the normalized frequency equals to the cutoff frequency.

Abstract: A configuration is provided with a laser medium 1 of a refractive index nc that is an isotropic medium and includes an upper surface and a lower surface, where at least one of the upper surface and the lower surface is bonded with a cladding 2 having a refractive index satisfying a relationship of no<nc<ne or ne<nc<no. This allows selective output of only polarized light generated by a refractive index in the cladding 2 smaller than the refractive index nc at a desired wavelength (e.g. 1535 nm) which can be implemented by using the isotropic medium.

Abstract: Plural signal beams enter a planar waveguide laser amplifier from different directions to follow different paths therein, which reduces a region not contributing to amplification where no signal beam passes. Plural signal beams follow different paths in the planar waveguide, and a second signal beam utilizes the gain of a portion of the planar waveguide that a first signal beam cannot utilize. By this configuration, a region not contributing to amplification of the signal beams in the planar waveguide laser amplifier can be reduced, causing to efficiently amplify plural signal beams.

Abstract: An object is to provide an optical device capable of relaxing a manufacturing condition for an optical waveguide used in the optical device. An optical device 500 is provided with an optical waveguide 200 including a core and a cladding optically joined together, and a temperature controller 600 that controls temperature of the optical waveguide, wherein the optical waveguide includes the core and the cladding formed such that a normalized frequency specified for light propagating through the optical waveguide changes across a cutoff frequency of a guided mode determined from a structure of the optical waveguide in a temperature range in which a refractive index of the core is higher than a refractive index of the clad. The temperature controller controls the temperature of the optical waveguide over a temperature range across temperature at which the normalized frequency equals to the cutoff frequency.

Abstract: A configuration is provided with a laser medium 1 of a refractive index nc that is an isotropic medium and includes an upper surface and a lower surface, where at least one of the upper surface and the lower surface is bonded with a cladding 2 having a refractive index satisfying a relationship of no<nc<ne or ne<nc<no. This allows selective output of only polarized light generated by a refractive index in the cladding 2 smaller than the refractive index nc at a desired wavelength (e.g. 1535 nm) which can be implemented by using the isotropic medium.

Abstract: Plural signal beams enter a planar waveguide laser amplifier from different directions to follow different paths therein, which reduces a region not contributing to amplification where no signal beam passes. Plural signal beams follow different paths in the planar waveguide, and a second signal beam utilizes the gain of a portion of the planar waveguide that a first signal beam cannot utilize. By this configuration, a region not contributing to amplification of the signal beams in the planar waveguide laser amplifier can be reduced, causing to efficiently amplify plural signal beams.

Abstract: A fixing device for use in an electrophotographic copying machine comprising a fixing plate having a width substantially equal to the maximum width of recording sheets in use and a heater disposed transversely of a fixing plate. The heater is divided into heater sections in the direction of widths of the recording sheets corresponding to the widths thereof. A temperature sensing element is associated with each of the divided heater sections and supplied power to the heater sections is controlled in response to the output of the temperature sensing element.