Abstract: A light communication device further includes a rigid substrate, a package, and a flexible substrate. The rigid substrate includes a first terminal arranged on a surface thereof and a second terminal having a first hole opened at the surface. The package includes a third terminal and a fourth terminal being provided on a side wall thereof and being electrically coupled to a signal electrode and a ground electrode of the signal processor, respectively. The flexible substrate includes a fifth terminal and a sixth terminal being electrically coupled to the third terminal and the fourth terminal, respectively. The fifth terminal is electrically coupled to the first terminal on the surface, and the sixth terminal, with being placed into the first hole, is electrically coupled to the second terminal.

Abstract: A light communication device further includes a rigid substrate, a package, and a flexible substrate. The rigid substrate includes a first terminal arranged on a surface thereof and a second terminal having a first hole opened at the surface. The package includes a third terminal and a fourth terminal being provided on a side wall thereof and being electrically coupled to a signal electrode and a ground electrode of the signal processor, respectively. The flexible substrate includes a fifth terminal and a sixth terminal being electrically coupled to the third terminal and the fourth terminal, respectively. The fifth terminal is electrically coupled to the first terminal on the surface, and the sixth terminal, with being placed into the first hole, is electrically coupled to the second terminal.

Abstract: A first circuit board has an electrode pattern, a ground pattern, a first through hole, and a second through hole. The first through hole penetrates through the electrode pattern. The second through hole penetrates through the ground pattern. A second circuit board has a signal line, an electrode terminal, and a ground terminal. The electrode terminal is extended from the signal line, and is electrically connected to the electrode pattern with the electrode terminal being inserted into the first through hole. The ground terminal is electrically connected to the ground pattern with the ground terminal being inserted into the second through hole, and has a width, a length, or an area or any combination thereof larger than a width, a length, or an area or any combination thereof of the electrode terminal.

Abstract: An optical modulating apparatus includes driver that is mounted on a printed circuit board such that a signal electrode pad and a ground electrode pad of the driver are exposed in an opening of the printed circuit board. An optical modulating device is mounted on the printed circuit board, opposing the driver across the opening. A flexible circuit board is disposed in the opening. An end of a signal terminal of the flexible circuit board is electrically connected to a signal electrode of the optical modulating device. An end of a ground terminal of the flexible circuit board is electrically connected to a ground electrode of the optical modulating device. The other end of the signal terminal is soldered to the signal electrode pad of the driver, and the other end of the ground terminal is soldered to the ground electrode pad of the driver.

Abstract: An optical modulating apparatus includes driver that is mounted on a printed circuit board such that a signal electrode pad and a ground electrode pad of the driver are exposed in an opening of the printed circuit board. An optical modulating device is mounted on the printed circuit board, opposing the driver across the opening. A flexible circuit board is disposed in the opening. An end of a signal terminal of the flexible circuit board is electrically connected to a signal electrode of the optical modulating device. An end of a ground terminal of the flexible circuit board is electrically connected to a ground electrode of the optical modulating device. The other end of the signal terminal is soldered to the signal electrode pad of the driver, and the other end of the ground terminal is soldered to the ground electrode pad of the driver.

Abstract: An optical apparatus which is reduced in the number of optical devices arranged on a main optical signal transmission path, thereby reducing the size and cost of the device, and which is improved in optical transmission quality. An optical amplifier includes an amplification medium, which is doped with an active material for optical amplification and to which pump light is introduced, for amplifying an optical signal to be output. A reflection-type variable optical attenuator includes a reflecting mirror for reflecting an input light to generate a reflected light, and a magneto-optical crystal arranged in a position where the input and reflected lights pass. The magneto-optical crystal is applied with a magnetic field to induce a Faraday rotation angle therein and thereby vary an attenuation amount of the amplified optical signal, and part of light transmitted through the reflecting mirror is converted, as input monitor light, into an electrical signal.

Abstract: In an optical switch device: output waveguides are arranged with such a pitch as to realize a split wavelength gap equal to or smaller than half of a gap between operating wavelengths of optical signals; at least two input waveguides are arranged with the same pitch; at least one slab waveguide spreads light from the input waveguides to be outputted to a grating element, condenses first light from the grating element to be outputted into the input waveguides, condenses second light from the grating element for each wavelength to be outputted into the output waveguides, and spreads light from the output waveguides to be outputted to the grating element; and the optical switch unit selects signals at an identical wavelength in adjacent output waveguides, and performs 2×2 switching of the signals so as to output the signals from the input waveguides.

Abstract: An optical apparatus which is reduced in the number of optical devices arranged on a main optical signal transmission path, thereby reducing the size and cost of the device, and which is improved in optical transmission quality. An optical amplifier includes an amplification medium, which is doped with an active material for optical amplification and to which pump light is introduced, for amplifying an optical signal to be output. A reflection-type variable optical attenuator includes a reflecting mirror for reflecting an input light to generate a reflected light, and a magneto-optical crystal arranged in a position where the input and reflected lights pass. The magneto-optical crystal is applied with a magnetic field to induce a Faraday rotation angle therein and thereby vary an attenuation amount of the amplified optical signal, and part of light transmitted through the reflecting mirror is converted, as input monitor light, into an electrical signal.

Abstract: In an optical switch device: output waveguides are arranged with such a pitch as to realize a split wavelength gap equal to or smaller than half of a gap between operating wavelengths of optical signals; at least two input waveguides are arranged with the same pitch; at least one slab waveguide spreads light from the input waveguides to be outputted to a grating element, condenses first light from the grating element to be outputted into the input waveguides, condenses second light from the grating element for each wavelength to be outputted into the output waveguides, and spreads light from the output waveguides to be outputted to the grating element; and the optical switch unit selects signals at an identical wavelength in adjacent output waveguides, and performs 2×2 switching of the signals so as to output the signals from the input waveguides.

Abstract: Light emitted from an optical fiber is collimated by a collimating lens. An optical filter with a slit is placed in the path of the collimated light. The slit can be moved along a direction perpendicular to the path of the collimated light. When the slit is on the center of the collimated beam, because the intensity of light is high at the center, the diffraction loss of the light is high. When the slit is on the edge, because the light intensity is low at the edge, the diffraction loss is low. The diffraction loss has a wavelength characteristic and can be controlled by adjusting the position of the slit in the collimated beam.

Abstract: An apparatus has first and second light sources, a plurality of filters, and an optical switch. The light sources output a light beam having a spectrum determined by a gain band thereof. The plurality of filters each have a reflection band included in the gain band. The optical switch selectively couples the filters to the light source. The first and second light sources provide pumping light to a single transmission line. The first and second filters are configured so as to not reflect signal light to be amplified.

Abstract: An optical switch includes a plurality of optical fibers arrayed at equal intervals and in parallel, each optical fiber having a central axis and having an end surface on one side of the optical switch. A single lens has a focal length and a central axis parallel to each fiber central axis, the lens disposed away from the fiber end surface at a distance corresponding to the focal length of the lens. A first mirror has a reflection surface perpendicular to the lens central axis, the first mirror removably disposed at a first position on the other side of the optical switch. A second mirror has a reflection surface inclined from the lens central axis, the second mirror removably disposed at the first position. One of the first and second mirrors is selectively disposed at the first position.

Abstract: A wavelength characteristic control device capable of variably controlling a wavelength characteristic in a satisfactory manner. A polarized light wavelength characteristic changing element has a wavelength characteristic such that the transmittances or reflectances of P- and S-polarized rays vary differently with respect to wavelength. Polarization variable control means subjects the plane of polarization of the polarized light incident on the polarized light wavelength characteristic changing element to rotatory control to change the ratio of the P-polarized ray to the S-polarized ray, thereby variably controlling the wavelength characteristic.

Abstract: A movable mirror having a mirror surface reflecting a light input from an input fiber collimator is moved in an arrow (1) direction so that the reflection frequency of the input light reflected by an optical filter can be variable. The light is reflected plural times between the mirror surface and the optical filter, directed to a fixed mirror by the mirror surface, reflected by the fixed mirror, and is connected to an output fiber collimator. By moving the movable mirror in parallel, the reflection count of the light between the optical filter and the mirror surface is variable. Therefore, the wavelength characteristic of the light is obtained as an accumulated wavelength characteristic depending on the reflection count.

Abstract: A wavelength characteristic control device capable of variably controlling a wavelength characteristic in a satisfactory manner. A polarized light wavelength characteristic changing element has a wavelength characteristic such that the transmittances or reflectances of P- and S-polarized rays vary differently with respect to wavelength. Polarization variable control means subjects the plane of polarization of the polarized light incident on the polarized light wavelength characteristic changing element to rotatory control to change the ratio of the P-polarized ray to the S-polarized ray, thereby variably controlling the wavelength characteristic.

Abstract: A wavelength characteristic control device capable of variably controlling a wavelength characteristic in a satisfactory manner. A polarized light wavelength characteristic changing element has a wavelength characteristic such that the transmittances or reflectances of P- and S-polarized rays vary differently with respect to wavelength. Polarization variable control means subjects the plane of polarization of the polarized light incident on the polarized light wavelength characteristic changing element to rotatory control to change the ratio of the P-polarized ray to the S-polarized ray, thereby variably controlling the wavelength characteristic.

Abstract: An optical switch includes a plurality of optical fibers arrayed at equal intervals and in parallel, each optical fiber having a central axis and having an end surface on one side of the optical switch. A single lens has a focal length and a central axis parallel to each fiber central axis, the lens disposed away from the fiber end surface at a distance corresponding to the focal length of the lens. A first mirror has a reflection surface perpendicular to the lens central axis, the first mirror removably disposed at a first position on the other side of the optical switch. A second mirror has a reflection surface inclined from the lens central axis, the second mirror removably disposed at the first position. One of the first and second mirrors is selectively disposed at the first position.

Abstract: Disclosed herein is an optical device including a fiber collimator and a plurality of fiber assemblies sequentially optically coupled to the fiber collimator by a reflected light path of a substantially parallel beam. The fiber collimator includes an optical fiber and a lens opposed to the optical fiber. Each fiber assembly includes an optical filter for providing the reflected light path, an optical fiber optically coupled to the optical filter by its transmitted light path, and a lens provided between the optical filter and this optical fiber. The lens of the i-th fiber assembly has a focal length equal to or greater than that of the lens of the (i−1)-th fiber assembly. With this configuration, a deviation in coupling loss or insertion loss due to beam divergence in the reflected light path can be reduced.

Abstract: A movable mirror having a mirror surface reflecting a light input from an input fiber collimator is moved in an arrow (1) direction so that the reflection frequency of the input light reflected by an optical filter can be variable. The light is reflected plural times between the mirror surface and the optical filter, directed to a fixed mirror by the mirror surface, reflected by the fixed mirror, and is connected to an output fiber collimator. By moving the movable mirror in parallel, the reflection count of the light between the optical filter and the mirror surface is variable. Therefore, the wavelength characteristic of the light is obtained as an accumulated wavelength characteristic depending on the reflection count.

Abstract: An apparatus has first and second light sources, a plurality of filters, and an optical switch. The light sources output a light beam having a spectrum determined by a gain band thereof. The plurality of filters each have a reflection band included in the gain band. The optical switch selectively couples the filters to the light source. The first and second light sources provide pumping light to a single transmission line. The first and second filters are configured so as to not reflect signal light to be amplified.