Abstract:
Provided is a terahertz wave generating/detecting apparatus and a method for manufacturing the same. The terahertz wave generating/detecting apparatus includes; a substrate having an active region and a transmitting region; a lower metal layer extending in a first direction on the active region and the transmitting region of the substrate; a graphene layer disposed on the lower metal layer on the active region; and upper metal layers extending in the first direction on the graphene layer of the active region and the substrate in the transmission region, wherein a terahertz wave is generated or amplified by a surface plasmon polariton that is induced on a boundary surface between the graphene layer and the lower metal layer by beated laser light applied to the graphene layer and the metal layer.
Abstract:
An optical signal generating apparatus according to an embodiment of the inventive concept includes a first optical intensity modulator for modulating a first optical signal to generate a 2N-level (where N is a positive integer) second optical signal in the form of a binary signal, a first optical amplifier for amplifying the second optical signal to generate a third optical signal, and a second optical intensity modulator for modulating the third optical signal to generate a 2N+1-level fourth optical signal in the form of a binary signal. The optical signal generating apparatus according to an embodiment of the inventive concept may generate a low-cost, high-quality optical signal by using an optical device to generate a multi-level optical signal. Additionally, the optical signal generating apparatus according to an embodiment of the inventive concept may generate a multi-level optical signal by sequentially performing optical modulation and optical amplification operations.
Abstract:
A terahertz wave generating module includes a bidirectional light source which provides a first dual-mode beam in a first direction and a second dual-mode beam in a second direction; a forward lens unit which focuses the first dual-mode beam; a photomixer unit which converts the first dual-mode beam focused by the forward lens unit into a terahertz wave; a backward lens unit which focuses the second dual-mode beam; and a light output unit which uses the second dual-mode beam focused by the backward lens unit as a light signal, wherein the bidirectional light source, the forward lens unit, the photomixer unit, the backward lens unit, and the light output unit are integrated in a housing.
Abstract:
Provided is a quarter-wavelength shifted distributed feedback laser diode. The laser diode includes a substrate having a laser diode section and a phase adjustment section, a waveguide layer on the substrate, a clad layer on the waveguide layer, a grating disposed in the clad layer in the laser diode section, an anti-reflection coating disposed on one side walls, of the substrate, the waveguide layer, and the clad layer, adjacent to the laser diode section, and a high reflection coating disposed on the other side walls, of the substrate, the waveguide layer, and the clad layer, adjacent to the phase adjustment section.
Abstract:
Provided is a tunable semiconductor laser including an active gain region in which an optical signal is generated according to a modulation signal, a mode control region in which a resonant mode is controlled according to a mode control signal, and a signal chirp of the optical signal is compensated according to a first compensation signal determined based on the modulation signal, and a distributed Bragg reflector (DBR) region in which an oscillation wavelength of the optical signal is determined based on a wavelength selection signal for the optical signal, a second compensation signal for compensating for a thermal chirp of the optical signal on a basis of the modulation signal, and a heater signal provided to a heater electrode.
Abstract:
The inventive concept relates to a beating signal monitoring module and a terahertz wave generation device and an optical signal monitoring device that including the beating signal monitoring module. The beating signal monitoring module includes a nonlinear unit generating an optical signal including a FWM light in response to a beating signal generated from a first light and a second light; a filter unit separating the FWM light from the optical signal and outputting the separated FWM light; and a monitoring unit monitoring the beating signal using the separated FWM light. The beating signal monitoring module and a terahertz wave generation device and an optical signal monitoring device that including the beating signal monitoring module can effectively monitor a beating signal being generated by two lasers using a Four Wave Mixing signal.
Abstract:
A contactless thickness measuring apparatus is provided which includes an terahertz transmitter configured to receive the first optical path signal from the coupler and to generate a terahertz continuous wave using the first optical signal and an applied bias; an optical delay line configured to delay the second optical path signal output from the coupler; and an terahertz receiver configured to receive the terahertz continuous wave penetrating a sample and to detect an optical current using the terahertz continuous wave and the second optical path signal delayed. A thickness of the sample is a value corresponding to the optical current which phase value becomes a constant regardless of a plurality of measurement frequencies.
Abstract:
An optical device may include first and second lasers generating first and second laser beams; and a photo detector detecting the first and second laser beams. The optical detector comprises a substrate, a first impurity layer on the substrate, an absorption layer on the first impurity layer and a second impurity layer on the absorption layer. The absorption layer generates a terahertz by a beating of the first and second laser beams and has a thickness of less than 0.2 μm.
Abstract:
An optical device may include first and second lasers generating first and second laser beams; and a photo detector detecting the first and second laser beams. The optical detector comprises a substrate, a first impurity layer on the substrate, an absorption layer on the first impurity layer and a second impurity layer on the absorption layer. The absorption layer generates a terahertz by a beating of the first and second laser beams and has a thickness of less than 0.2 μm.