Abstract: Provided is an optical device module that can improve miniaturization and integration. The optical device module includes a semiconductor optical amplifier having a buried structure and including a first active layer buried in a clad layer disposed on a first substrate, an optical modulator in which a sidewall of a second active layer disposed in a direction of the first active layer on a second substrate junctioned to the first substrate is exposed, the optical modulator having a ridge structure, and at least one multi-mode interference coupler in which the second active layer junctioned to the first active layer is buried in the clad layer, the multi-mode interference coupler sharing the second active layer on the second substrate between the optical modulator and the semiconductor optical amplifier and integrated with the second optical device.

Abstract: Provided is a self-oscillation communication module in which an optical device, a solar battery, and a radio frequency (RF) device are monolithic-integrated. When an active layer of the optical device contains In(Ga)As quantum dots, the optical device can emit light ranging from 800 to 1600 nm and transmit signals at a high speed of 20 Gbps or higher. Since a light absorption layer of the solar battery is formed of InGa(Al)P which has a higher bandgap than silicon and high visible light absorptivity, the solar battery can generate a large current even with a very small light reception area. Therefore, the self-oscillation communication module can always operate using the solar battery without an external power source even in polar regions and deserts and can perform optical communication or high-frequency wireless communication with a wide frequency range.

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: A quantum dot laser diode and a method of fabricating the same are provided. The quantum dot laser diode includes: a first clad layer formed on an InP substrate; a first lattice-matched layer formed on the first clad layer; an active layer formed on the first lattice-matched layer, and including at least one quantum dot layer formed of an InAlAs quantum dot or an InGaPAs quantum dot which is grown by an alternate growth method; a second lattice-matched layer formed on the active layer; a second clad layer formed on the second lattice-matched layer, and an ohmic contact layer formed on the second clad layer.

Abstract: Provided are a high-efficiency solar cell, which converts light energy of incident light into electrical energy, and a method of manufacturing the same. An upper ohmic layer is formed at a predetermined tilt angle less than 45° and an ohmic electrode is deposited on the upper ohmic layer so as to reduce shadow loss due to the ohmic electrode and lessen contact resistance.

Abstract: Provided is a method of forming quantum dots, including: forming a buffer layer on an InP substrate so as to be lattice-matched with the InP substrate; and sequentially alternately depositing In(Ga)As layers and InAl(Ga)As or In(Ga, Al, As)P layers that are greatly lattice-mismatched with each other on the buffer layer so as to form In(Ga, Al)As or In(Ga, Al, P)As quantum dots.

Abstract: An optical amplifier includes a passive waveguide region and an active waveguide region. The passive waveguide region is configured to receive an incident optical signal and adjust a mode of the optical signal. The active waveguide region is integrated to the passive waveguide region and configured to perform gain modulation on the optical signal received from the passive waveguide region by changing density of carriers in response to a current applied to the active waveguide region. Internal loss of the active waveguide region is adjusted to produce a resonance effect and thereby to increase bandwidth of the active waveguide. Therefore, the optical amplifier can have a wide bandwidth under a low-current condition.

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: Provided are a quantum dot laser diode and a method of manufacturing the same. The method of manufacturing a quantum dot laser diode includes the steps of: forming a grating structure layer including a plurality of gratings on a substrate; forming a first lattice-matched layer on the grating structure layer; forming at least one quantum dot layer having at least one quantum dot on the first lattice-matched layer; forming a second lattice-matched layer on the quantum dot layer; forming a cladding layer on the second lattice-matched layer; and forming an ohmic contact layer on the cladding layer. Consequently, it is possible to obtain high gain at a desired wavelength without affecting the uniformity of quantum dots, so that the characteristics of a laser diode can be improved.

Abstract: Provided is a self-oscillation communication module in which an optical device, a solar battery, and a radio frequency (RF) device are monolithic-integrated. When an active layer of the optical device contains In(Ga)As quantum dots, the optical device can emit light ranging from 800 to 1600 nm and transmit signals at a high speed of 20 Gbps or higher. Since a light absorption layer of the solar battery is formed of InGa(Al)P which has a higher bandgap than silicon and high visible light absorptivity, the solar battery can generate a large current even with a very small light reception area. Therefore, the self-oscillation communication module can always operate using the solar battery without an external power source even in polar regions and deserts and can perform optical communication or high-frequency wireless communication with a wide frequency range.

Abstract: Provided are a quantum dot laser diode and a method of manufacturing the same. The method of manufacturing a quantum dot laser diode includes the steps of: forming a grating structure layer including a plurality of gratings on a substrate; forming a first lattice-matched layer on the grating structure layer; forming at least one quantum dot layer having at least one quantum dot on the first lattice-matched layer; forming a second lattice-matched layer on the quantum dot layer; forming a cladding layer on the second lattice-matched layer; and forming an ohmic contact layer on the cladding layer. Consequently, it is possible to obtain high gain at a desired wavelength without affecting the uniformity of quantum dots, so that the characteristics of a laser diode can be improved.

Abstract: A distributed feedback (DFB) quantum dot semiconductor laser structure is provided. The DFB quantum dot semi-conductor laser structure includes: a first clad layer formed on a lower electrode; an optical waveguide (WG) formed on the first clad layer; a grating structure layer formed on the optical WG and including a plurality of periodically disposed gratings; a first separate confinement hetero (SCH) layer formed on the grating structure layer; an active layer formed on the first SCH layer and including at least a quantum dot; a second SCH layer formed on the active layer; a second clad layer formed on the second SCH layer; an ohmic layer formed on the second clad layer; and an upper electrode formed on the ohmic layer. Accordingly, an optical WG is disposed on the opposite side of the active layer from the grating structure layer, thereby increasing single optical mode efficiency.

Abstract: The present invention provides a transceiver module having advantages of minimizing the number of optical parts by using an optical collimator to which a lens having the same shape as a diameter of an optical fiber is attached on a light input/output end. An transceiver module according to the present invention includes, laser diode for generating an optical signal to transmit, a first photodiode for controlling the laser diode, a second and third photodiodes for receiving an optical signal of a first and second wavelengths, and an optical collimator formed at a light input/output end. On the optical collimator, a lens having an optical fiber shape is attached in a direction the light proceeds.

Abstract: A distributed feedback (DFB) quantum dot semiconductor laser structure is provided. The DFB quantum dot semi-conductor laser structure includes: a first clad layer formed on a lower electrode; an optical waveguide (WG) formed on the first clad layer; a grating structure layer formed on the optical WG and including a plurality of periodically disposed gratings; a first separate confinement hetero (SCH) layer formed on the grating structure layer; an active layer formed on the first SCH layer and including at least a quantum dot; a second SCH layer formed on the active layer; a second clad layer formed on the second SCH layer; an ohmic layer formed on the second clad layer; and an upper electrode formed on the ohmic layer. Accordingly, an optical WG is disposed on the opposite side of the active layer from the grating structure layer, thereby increasing single optical mode efficiency.

Abstract: Provided are a quantum dot laser diode and a method of manufacturing the same. The method of manufacturing a quantum dot laser diode includes the steps of: forming a grating structure layer including a plurality of gratings on a substrate; forming a first lattice-matched layer on the grating structure layer; forming at least one quantum dot layer having at least one quantum dot on the first lattice-matched layer; forming a second lattice-matched layer on the quantum dot layer; forming a cladding layer on the second lattice-matched layer; and forming an ohmic contact layer on the cladding layer. Consequently, it is possible to obtain high gain at a desired wavelength without affecting the uniformity of quantum dots, so that the characteristics of a laser diode can be improved.

Abstract: Provided is a method of forming quantum dots, including: forming a buffer layer on an InP substrate so as to be lattice-matched with the InP substrate; and sequentially alternately depositing In(Ga)As layers and InAl(Ga)As or In(Ga, Al, As)P layers that are greatly lattice-mismatched with each other on the buffer layer so as to form In(Ga, Al)As or In(Ga, Al, P)As quantum dots.

Abstract: The present invention provides a transceiver module having advantages of minimizing the number of optical parts by using an optical collimator to which a lens having the same shape as a diameter of an optical fiber is attached on a light input/output end. An transceiver module according to the present invention includes, laser diode for generating an optical signal to transmit, a first photodiode for controlling the laser diode, a second and third photodiodes for receiving an optical signal of a first and second wave lengths, and an optical collimator formed at a light input/output end. On the optical collimator, a lens having an optical fiber shape is attached in a direction the light proceeds.

Abstract: A wavelength stabilization module having a light-receiving element array and a method of manufacturing the same are disclosed.

Abstract: A system for monitoring an optical output/wavelength is employed to be used for a WDM system having a narrow channel space by structuring an etalon and photodiode as an integrated structure.

Abstract: A system for monitoring an optical output/wavelength is employed to be used for a WDM system having a narrow channel space by structuring an etalon and photodiode as an integrated structure.