Abstract:
A micro-resonator sensor uses an evanescent wave of a total reflection mirror. The sensor includes an input waveguide for guiding inspection light incidented on one end section to the other section. A total reflection mirror is disposed at the other section of the input waveguide such that an incident angle made with the input waveguide is larger than a total reflection threshold angle at which the inspection light is totally reflected, and includes a receptor provided on the other side from the side on which the inspection light is incidented and combined with a measurement-subject material. An output waveguide is disposed at a certain output angle relative to the total reflection mirror for outputting a reflection light whose intensity changes according to the measurement-subject material due to an interaction between the evanescent wave generated by the inspection light incidented to the total reflection mirror and the measurement-subject material.
Abstract:
A metal/semiconductor junction Schottky diode optical device using a distortion grown layer is described. A plurality of GaAs mirror and AlAs mirror layers are periodically grown on a semi-insulating GaAs substrate. An n+ or p+ semiconductor layer is formed on the GaAs mirror and AlAs mirror layers. A GaAs buffer layer is formed on the semiconductor layer to grow a Schottky metal layer serving as an electrode and a mirror. A multiple quantum well structure having an electro-optical absorption characteristic is positioned between the semiconductor layer and Schottky metal layer, for constructing a diode with the metal layer/multiple quantum well structure. At least a part of the mirror layers and diode are formed with a layer in order to have resonance and non-resonance conditions between the metal layer and mirror layers. The substrate on which the diode is formed has an opposite side formed with an optical non-reflective layer.
Abstract:
Provided is an optical device delaying light by using negative Goos-Hanchen shift. The optical device includes an optical waveguide adapted to guide and emit an incident light, a first reflection layer disposed at one side of the optical waveguide, and a second reflection layer disposed at the other side of the optical waveguide. At least one of the first and the second reflection layers is made of a material having characteristics of negative Goos-Hanchen shift.
Abstract:
Provided is a signal amplification apparatus with advanced linearization, the signal amplification apparatus including: a driving unit having a structure of a cascode amplifier including a first active element and a second active element and outputting an amplification signal in which an input signal is amplified, to an output terminal; a third active element receiving a signal diverged between the first active element and the second active element while gate and drain terminals of the third active element are shorted; a fourth active element of which gate and drain terminals are connected to a source terminal of the third active element; and a fifth active element of which gate terminal is connected to the drain terminal of the fourth active element, outputting a non-linear signal having an opposite phase to the amplification signal to the output terminal so as to cancel a third-order inter-modulation distortion component included in the input signal. An amplification signal in which an input signal is amplified is combined with a non-linear signal having an opposite phase to the amplification signal and a low gain and is output so that a third-order inter-modulation distortion component included in the input signal can be cancelled and a signal with advanced linearity can be output.
Abstract:
A micro resonator sensor includes a main waveguide, a resonance waveguide and optical path changing means. Optical path changing means are installed at apex regions contacting with adjacent optical waveguides forming the resonance waveguide and reflect at least a part of the split optical signal inputted into the resonance waveguide to circulate the split optical signal inside the resonance waveguide. The micro resonator sensor can be manufactured without an excessive radiation loss and can be manufactured as an on-chip.
Abstract:
Disclosed is an ultrafast optical switching device having two types of multiple quantum well structures to be connected with each other, the device comprising a semi-insulating substrate; and a first and a second multiple quantum well structure formed sequentially on the substrate and united with each other to produce a double-junction multiple quantum well structure. Each of the multiple quantum well structures has nonlinear optical effects and two life time constants present while switching off in the device. One of the life time constants corresponds to a short life time constant to be determined dependent on electrons in the double-junction multiple quantum well structure and the other of the life time constants corresponds to a long life time constant to be determined dependent on holes and lattices therein. The multiple quantum well structures are formed in such a manner that short life time constants thereof may be in-phase with each other and long life time constants thereof may be out-of-phase to each other. The multiple quantum well structures are formed differently from each other in composition.
Abstract:
Disclosed is an operation principle and an epitaxial structure of resonant tunneling opto-electronic device. According to the present invention, the photo-generated holes stored in front of the double barrier quantum well structure by light illumination. As a result, a large potential drop occurs in the double barrier quantum well structure. And a peak signal of the opto-electronic resonant tunneling device is generated at a relatively lower voltage illumination to one generated before introducing the light into the device. An amount of photocurrent is 10.sup.3 times and over as compared to the conventional p-i-n diode because a resonant tunneling current is optically controlled by light illumination. So that, it is possible to drive peripheral circuit without use of additional amplifiers for amplifying an output signal from the opto-electronic device.
Abstract:
Provided is a signal amplification apparatus with advanced linearization, the signal amplification apparatus including: a driving unit having a structure of a cascode amplifier including a first active element and a second active element and outputting an amplification signal in which an input signal is amplified, to an output terminal; a third active element receiving a signal diverged between the first active element and the second active element while gate and drain terminals of the third active element are shorted; a fourth active element of which gate and drain terminals are connected to a source terminal of the third active element; and a fifth active element of which gate terminal is connected to the drain terminal of the fourth active element, outputting a non-linear signal having an opposite phase to the amplification signal to the output terminal so as to cancel a third-order inter-modulation distortion component included in the input signal. An amplification signal in which an input signal is amplified is combined with a non-linear signal having an opposite phase to the amplification signal and a low gain and is output so that a third-order inter-modulation distortion component included in the input signal can be cancelled and a signal with advanced linearity can be output.
Abstract:
A micro resonator sensor includes a main waveguide, a resonance waveguide and optical path changing means. Optical path changing means are installed at apex regions contacting with adjacent optical waveguides forming the resonance waveguide and reflect at least a part of the split optical signal inputted into the resonance waveguide to circulate the split optical signal inside the resonance waveguide. The micro resonator sensor can be manufactured without an excessive radiation loss and can be manufactured as an on-chip.
Abstract:
A micro-resonator sensor using an evanescent wave of a total reflection mirror is disclosed. A main waveguide includes an input hole to which a optical signal is inputted and an output hole from which the optical signal is outputted, and a optical coupling region at which a portion of the optical signal inputted through the input hole is branched. A resonant waveguide includes a optical coupling waveguide optically coupled with the optical coupling region of the main waveguide to receive the branch optical signal branched from the main waveguide and a plurality of circumferential waveguides. The optical coupling waveguide and the plurality of circumferential waveguides are disposed in a polygonal shape. Optical path changing units are disposed at vertex regions to which the optical coupling waveguide and the circumferential waveguides are connected to reflect at least a portion of the branch optical signal inputted to the resonant waveguide so as to turn around within the resonant waveguide. At least one of the optical path changing units disposed at the vertex regions to which the circumferential waveguides are connected is a total reflection mirror with a receptor provided on the other side from the side on which the branch signal is inputted and combining with a measurement-subject material. The circumferential waveguide that inputs the branch optical signal to the total reflection mirror is disposed such that an incident angle relative to the total reflection mirror is larger than a total reflection threshold angle. Because the resonator is configured by using the total reflection mirrors, the micro-resonator sensor can be fabricated with an ultra-compact size without an excessive radiation loss. Also, because all the elements are integrated on a single wafer, the micro-resonator sensor can be fabricated as an on-chip, whereby an ultra-compact optical sensor module applicable to mobile terminals can be manufactured.