Abstract:
A ridge-type semiconductor laser is provided. The ridge-type semiconductor laser includes a pattern for a current inflow path control formed on an active layer and having an opening thereinside controlling a current inflow path with a width W1, and a ridge formed on the pattern for a current inflow path control, with a width W2 greater than W1 and burying the opening with a width W1 and controlling an optical mode. The ridge-type semiconductor laser improves the characteristics of a laser by separately controlling the extent that current is spread in the space, and the extent that optical mode is spread in the space, to maximize the coincidence of the respective space distributions of the current and the optical mode.
Abstract:
The inventive concept provides avalanche photo diodes and methods of manufacturing the same. The avalanche photo diode may include a substrate, a light absorption layer formed on the substrate, a clad layer formed on the light absorption layer, an active region formed in the clad layer, a guard ring region formed around the active region, and an insulating region formed between the guard ring region and the active region.
Abstract:
The inventive concept provides avalanche photo diodes and methods of manufacturing the same. The avalanche photo diode may include a substrate, a light absorption layer formed on the substrate, a clad layer formed on the light absorption layer, an active region formed in the clad layer, a guard ring region formed around the active region, and an insulating region formed between the guard ring region and the active region.
Abstract:
Provided is a wavelength division multiplexed-passive optical network (WDM-PON) apparatus. The WDM-PON includes an optical source unit, an optical mux, and a chirped Bragg grating. The optical source unit generates an optical signal. The optical mux receives the optical signal from the optical source unit through one end of the optical mux, multiplexes the optical signal, and outputs the multiplexed optical signal. The chirped Bragg grating is connected to the other end of the optical mux. The chirped Bragg grating again reflects the optical signal having passed the optical mux to re-input a certain portion of the optical signal into the optical mux and the optical source unit. The optical mux performs a spectrum slicing on the re-inputted optical signal and operates the optical source unit using a channel wavelength of the optical mux as a main oscillation wavelength.
Abstract:
Provided is a mask pattern for selective area growth of a semiconductor layer and a selective area growth method for a semiconductor layer for independently controlling a growth rate and a strain of the semiconductor layer. The selective area growth method includes: forming a plurality of pairs of first mask patterns, the first mask patterns in each pair including a first open area therebetween, the first open area having a width that is wider than a distance causing overgrowth of the semiconductor layer, the pairs of the first mask patterns repeatedly arranged with a period P therebetween; wherein controlling a growth rate and a strain of the semiconductor layer formed on the first open area by adjusting the period P.
Abstract:
Provided is a photo detector. The photo detector includes: an avalanche photodiode; a bias circuit supplying a bias voltage to one end of the avalanche photodiode; a detection circuit connected to the other end of the avalanche photodiode and detecting a photoelectric current occurring in the avalanche photodiode; and a coupling capacitor connected to the one end or the other end of the avalanche photodiode and supplying a coupling voltage to drive the avalanche photodiode in a Geiger mode.
Abstract:
A semiconductor optical device includes a first mode converting core, a light amplification core, a second mode converting core, and a light modulation core disposed in a first mode converting region, a light amplification region, a second mode converting region, and a light modulating region of a semiconductor substrate, respectively, and a current blocking section covering at least sidewalls and a top surface of the light amplification core. The first mode converting core, the light amplification core, the second mode converting core, and the light modulation core are arranged along one direction in the order named, and are connected to each other in butt joints. The current blocking section includes first, second, and third cladding patterns sequentially stacked. The second cladding pattern is doped with dopants of a first conductivity type, and the first and third cladding patterns are doped with dopants of a second conductivity type.
Abstract:
Provided are a semiconductor optical amplifier and an optical signal processing method using the same. The reflective semiconductor optical amplifier includes: an optical signal amplification region operating to allow a downward optical signal incident from the external to obtain a gain; and an optical signal modulation region connected to the optical signal amplification region and generating a modulated optical signal. The downward optical signal is amplified through a cross gain modulation using the modulated optical signal and is outputted as an upward optical signal.
Abstract:
Disclosed is a system of a dynamic range three-dimensional image, including: an optical detector including a gain control terminal capable of controlling an optical amplification gain; a pixel detecting module for detecting a pixel signal for configuring an image by receiving an output of the optical detector; a high dynamic range (HDR) generating module for acquiring a dynamic range image by generating a signal indicating a saturation degree of the pixel signal and combining the pixel signal based on the pixel signal detected by the pixel detecting module; and a gain control signal generating module generating an output signal for supplying required voltage to the gain control terminal of the optical detector based on the magnitude of the signal indicating the saturation degree of the pixel signal.
Abstract:
Provided are a high-speed superluminescent diode, a method of manufacturing the same, and a wavelength-tunable external cavity laser including the same. The superluminescent diode includes a substrate having an active region and an optical mode size conversion region, waveguides including an ridge waveguide in the active region and a deep ridge waveguide in the optical mode size conversion region connected to the active waveguide, an electrode disposed on the ridge waveguide; planarizing layers disposed on sides of the ridge waveguide and the deep ridge waveguide on the substrate, and a pad electrically connected to the electrode, the pad being disposed on the planarizing layers outside the active waveguide.