Abstract: A temperature control device for controlling temperature of an object substance, the temperature control device includes: a pulse width modulator for changeably providing current directions of a providing current; a low pass filter; a Peltier device electrically connected to the pulse width modulator via the low pass filter; and a diode placed the low pass filter in parallel.

Abstract: A temperature control device for controlling temperature of an object substance, the temperature control device includes: a pulse width modulator for changeably providing current directions of a providing current; a low pass filter; a Peltier device electrically connected to the pulse width modulator via the low pass filter; and a diode placed the low pass filter in parallel.

Abstract: An optical device module includes an optical device, a soaking unit fixed to one surface of the optical device, a heating/cooling unit fixed to one surface of the soaking unit, a heat-insulating unit fixed to one surface of the heating/cooling unit, and a package that houses the optical device, the soaking unit, the heating/cooling unit, and the heat-insulating unit and to which the heat-insulating unit is fixed. The heating/cooling unit heats the optical device using self-generated heat or cools the optical device via the soaking unit.

Abstract: A wavelength selective switch of the invention separates WDM light coming out from an input fiber of a fiber collimator array according to its wavelength, in a diffraction grating, and reflects each wavelength channel proceeding in different directions by MEMS mirrors corresponding to a mirror array. In the MEMS mirrors, the angles of their reflecting surfaces are set corresponding to the location of the output port which is set in the output address of the wavelength channel to be injected. For each of the wavelength channels that reach the target output port, one part of each is reflected by the end face of an output fiber, and the reflected light is returned to the input port, and sent to a channel monitor via an optical circulator, so that the optical power corresponding to each wavelength channel is monitored.

Abstract: An optical device module includes an optical device with a plurality of electrodes disposed at predetermined positions, a substrate disposed oppositely to the optical device and with wiring patterns for connecting to the electrodes, and a wiring which connects the electrodes to the wiring patterns.

Abstract: A low-priced mirror device that has a simple structure and high reliability and can prevent excessive light input. A reflecting surface is constructed to be rotatable, and the mirror device is comprised of a mirror whose reflecting surface is rotated by a radiation pressure of an incident light that is supplied and restoring force generating mechanisms that can generate a restoring force attempting to restore the mirror that has been rotated by the radiation pressure of the incident light to an original position.

Abstract: A wavelength selective switch of the invention, separates WDM light coming out from an input fiber of a fiber collimator array according to its wavelength, in a diffraction grating, and reflects each wavelength channel proceeding in different directions by MEMS mirrors corresponding to a mirror array. In the MEMS mirrors, the angles of their reflecting surfaces are set corresponding to the location of the output port which is set in the output address of the wavelength channel to be injected. For each of the wavelength channels that reach the target output port, one part of each is reflected by the end face of an output fiber, and the reflected light is returned to the input port, and sent to a channel monitor via an optical circulator, so that the optical power corresponding to each wavelength channel is monitored.

Abstract: An optical device includes a small and low-cost variable polarization plane rotator that can control a rotation angle of the polarization plane easily. A variable polarization plane rotator is provided with a ?/4 phase plate having an optical axis in the same direction as, or at a 90 degree angle relative to, a polarization direction of an input light beam. A phase difference variable element has an optical axis at a ±45 degree angle relative to the optical axis of the ?/4 phase plate, to apply a variable phase difference between the polarization components parallel to and perpendicular to the optical axis thereof. A phase difference adjustment section adjusts the variable phase difference of the phase difference variable element, wherein the input light beam after being transmitted through the phase difference variable element to form elliptically polarized light or circularly polarized light, is transmitted through the ?/4 phase plate to form linearly polarized light.

Abstract: An optical device module includes an optical device, a soaking unit fixed to one surface of the optical device, a heating/cooling unit fixed to one surface of the soaking unit, a heat-insulating unit fixed to one surface of the heating/cooling unit, and a package that houses the optical device, the soaking unit, the heating/cooling unit, and the heat-insulating unit and to which the heat-insulating unit is fixed. The heating/cooling unit heats the optical device using self-generated heat or cools the optical device via the soaking unit.

Abstract: An optical device module includes an optical device with a plurality of electrodes disposed at predetermined positions, a substrate disposed oppositely to the optical device and with wiring patterns for connecting to the electrodes, and a wiring which connects the electrodes to the wiring patterns.

Abstract: An optical device includes a small and low-cost variable polarization plane rotator that can control a rotation angle of the polarization plane easily. A variable polarization plane rotator is provided with a ?/4 phase plate having an optical axis in the same direction as, or at a 90 degree angle relative to, a polarization direction of an input light beam. A phase difference variable element has an optical axis at a ±45 degree angle relative to the optical axis of the ?/4 phase plate, to apply a variable phase difference between the polarization components parallel to and perpendicular to the optical axis thereof. A phase difference adjustment section adjusts the variable phase difference of the phase difference variable element, wherein the input light beam after being transmitted through the phase difference variable element to form elliptically polarized light or circularly polarized light, is transmitted through the ?/4 phase plate to form linearly polarized light.

Abstract: An etalon includes an analyzer, a first ?/4 plate having an optical axis forming a 45 degree angle with respect to an optical axis of the analyzer and receiving a light transmitted via the analyzer, and a second ?/4 plate having an optical axis which is parallel to or 90 degrees to the optical axis of the first ?/4 plate and receiving a light transmitted via the first ?/4 plate. A reflection may occur between the first and second ?/4 plates.

Abstract: A method of controlling a polarization scrambler which changes a state of polarization of incident light with time in accordance with a driving voltage. The method includes a first step of applying the driving voltage so that the polarization state of the incident light changes from a starting point and makes N rotations (where N is a positive integer) around a longitude line of the Poincare sphere in a unit time, and a second step of applying the driving voltage so that the polarized light at the starting point on the Poincare sphere becomes the polarized light at an arbitrary position on the Poincare sphere instantaneously. The first step and the second step are repeated.

Abstract: An optical device includes a small and low-cost variable polarization plane rotator that can control a rotation angle of the polarization plane easily. A variable polarization plane rotator is provided with a &lgr;/4 phase plate having an optical axis in the same direction as, or at a 90 degree angle relative to, a polarization direction of an input light beam. A phase difference variable element has an optical axis at a ±45 degree angle relative to the optical axis of the &lgr;/4 phase plate, to apply a variable phase difference between the polarization components parallel to and perpendicular to the optical axis thereof. A phase difference adjustment section adjusts the variable phase difference of the phase difference variable element, wherein the input light beam after being transmitted through the phase difference variable element to form elliptically polarized light or circularly polarized light, is transmitted through the &lgr;/4 phase plate to form linearly polarized light.

Abstract: A method of controlling a polarization scrambler which changes a state of polarization of incident light with time in accordance with a driving voltage. The method includes a first step of applying the driving voltage so that the polarization state of the incident light changes from a starting point and makes N rotations (where N is a positive integer) around a longitude line of the Poincare sphere in a unit time, and a second step of applying the driving voltage so that the polarized light at the starting point on the Poincare sphere becomes the polarized light at an arbitrary position on the Poincare sphere instantaneously. The first step and the second step are repeated.

Abstract: An etalon includes an analyzer, a first &lgr;/4 plate having an optical axis forming a 45 degree angle with respect to an optical axis of the analyzer and receiving a light transmitted via the analyzer, and a second &lgr;/4 plate having an optical axis which is parallel to or 90 degrees to the optical axis of the, first &lgr;/4 plate and receiving a light transmitted via the first &lgr;/4 plate. A reflection may occur between the first and second &lgr;/4 plates.

Abstract: An object of the invention is to provide a small and low-cost variable polarization plane rotator that can control a rotation angle of the polarization plane easily, and an optical device using the same.

Abstract: To increase the size of dot printed on a print medium with an on-demand multi-nozzle ink jet head, at least two unit pulses are applied in succession to a piezoelectric element which varies the volume of an ink chamber. The unit pulse has a pulse width substantially equal to a period of Helmholtz natural oscillation determined based on dimensions, materials, and physical properties of an ink channel and the piezoelectric element and other components relating to oscillation. An off duration between adjacent unit pulses applied in succession to the piezoelectric element is preferably set one fifth to one fourth of the unit pulse width.

Abstract: An on-demand ink jet head includes a plurality of piezoelectric elements in alignment with one another with one end of each facing in the same direction. The end of each piezoelectric element is bonded by an adhesive material to a diaphragm which, together with a nozzle plate, forms a pressurizing chamber. To confine the fluid state adhesive material expelled out of the endmost piezoelectric elements, a dummy piezoelectric element is disposed outside each endmost piezoelectric element. The adhesive material, when dried, serves as a damper of the piezoelectric element for damping unwanted vibrations of the piezoelectric elements. By the provision of the dummy piezoelectric elements, the distribution of the adhesive material becomes substantially even between the piezoelectric elements, resulting in uniform operations of the piezoelectric elements.

Abstract: A piezoelectric element is driven by a predetermined pulse width in the range of 60 to 100% of the Helmholtz resonance vibration period of an ink vibration system comprising an orifice, a pressurizing chamber, a restrictor, the piezoelectric element, and an elastic material.