Abstract: Provided are a wavelength swept source apparatus and a method for controlling thereof. According to the provided apparatus and method, single mode light is generated, a basic optical comb is generated by modulating the generated single mode light, and a plurality of optical combs having different a frequency band from that of the basic optical comb is generated by modulating the plurality of light rays. The plurality of light rays and light rays included in the plurality of optical combs are sequentially emitted according to frequencies of the plurality of light rays and the light rays included in the plurality of optical combs. A value of a control variable is adjusted based on a characteristic of the generated single mode light, the plurality of light rays, the light rays included in the plurality of optical combs, and the emitted light rays.

Abstract: Provided are a wavelength swept source apparatus and a method for operating thereof. According to the provided apparatus and method, single mode light is generated, a basic optical comb including a plurality of light rays having identical frequency differences with adjacent light rays is generated by modulating the generated single mode light, and a plurality of optical combs, that includes same number of light rays as the plurality of light rays, has a different frequency band from that of the basic optical comb, and is distributed in a wider frequency band than that in which the basic optical comb is distributed, is generated by modulating the plurality of light rays. The plurality of light rays and light rays included in the plurality of optical combs are sequentially emitted according to frequencies of the plurality of light rays and the light rays included in the plurality of optical combs.

Abstract: Provided is a distributed feedback-laser diode (DFB-LD) and manufacturing method thereof. The DFB-LD includes a substrate; a lower clad layer having a grating on the substrate; an active waveguide extended in a first direction on the lower clad layer; an upper clad layer on the active waveguide; a signal pad on the upper clad layer; and at least one ground pad spaced apart from the active waveguide, the upper clad layer, and the signal pad in a second direction crossing the first direction, the at least one ground pad being coupled to the lower clad layer.

Abstract: Provided is a method of manufacturing a ridge waveguide type semiconductor laser diode, the method including sequentially forming, on a substrate, a lower clad layer, an active layer, a first upper clad layer, and a second upper clad layer; forming an insulating mask on the second upper clad layer; wet-etching the second upper clad layer by using the insulating mask to form channels passing through the second upper clad layer and a ridge between the channels; and performing dry-etching by using the insulating mask to form trenches that are extended from the channels and pass through the first upper clad layer.

Abstract: Provided is a wavelength tunable light source including a super luminescent diode (SLD) generating lights in a predetermined wavelength band, a voltage generating unit generating first and second voltages, a first filter receiving the first voltage from the voltage generating unit, receiving the lights from the SLD, and transmitting, as second lights, lights corresponding to wavelengths separated by a free spectral range (FSR) from each other among the received lights, a second filter receiving the second voltage from the voltage generating unit, receiving the second lights from the first filter, and transmitting, as a third light, a light corresponding to one wavelength among the separated wavelengths among the received second light, and a reflective mirror disposed at an output end of the second filter and reflects the third light transmitted from the second filter.

Abstract: Provided is a multi-wavelength optical source generator. The multi-wavelength optical source generator includes: a gain part generating a plurality of lights through a plurality of gain waveguides; a reflective part transmitting or reflecting lights provided from each of the plurality of gain waveguides according to a wavelength; and a multiplexing part multiplexing a plurality of lights transmitted and outputted through the reflective part.

Abstract: Distributed feedback-laser diodes are provided. The distributed feedback-laser diode may include a substrate, a lower cladding layer having a grating on the substrate, an active layer disposed on the lower cladding layer, a first upper cladding layer disposed on the active layer, a phase-shift region extending in a first direction on the first upper cladding layer, and a ridge waveguide layer extending in a second direction crossing the first direction on the phase-shift region.

Abstract: Provided are a spot size converter and a method of manufacturing the spot size converter. The method includes stacking a lower clad layer, a core layer, and a first upper clad layer on a substrate, tapering the first upper clad layer and the core layer in a first direction on a side of the substrate, forming a waveguide layer on the first upper clad layer and the lower clad layer, and etching the waveguide layer, the first upper clad layer, the core layer, and the lower clad layer such that the waveguide layer is wider than a tapered portion of the core layer on the side of the substrate and has the same width as that of the core layer on another side of the substrate.

Abstract: Provided is a multichannel transmitter optical module which includes a plurality of light source units configured to generate light, a plurality of an electro-absorption modulators (EAMs) configured to modulate the generated light to an optical signal through a radio frequency (RF) signal, a plurality of RF transmission lines configured to apply the RF signal to the EAMs, and a combiner configured to combine the modulated optical signal. The RF transmission lines are connected to the EAMs in a traveling wave (TW) electrode manner. The multichannel transmitter optical module has alleviated crosstalk and is compactly integrated to have a small size.

Abstract: Disclosed is a transmitter optical module which includes an electro-absorption modulated laser modulating a light into an optical signal through a high-frequency electrical signal; a first sub-mount transferring the high-frequency signal to the electro-absorption modulated laser; and a second sub-mount receiving the high-frequency signal from the electro-absorption modulated laser to terminate the electro-absorption modulated laser. A length of a first wire connecting the first sub-mount and the electro-absorption modulated laser is different from a length of a second wire connecting the second sub-mount and the electro-absorption modulated laser.

Abstract: Disclosed is a transmitter optical module which includes a first package generating an optical signal; a second package bonded with the first package by using chip-to-chip bonding, having a silicon optical circuit platform structure, and amplifying the optical signal; and an optical waveguide forming a transmission path of the optical signal from the first package to the second package.

Abstract: Provided are a distributed feedback laser diode and a manufacturing method thereof. The distributed feedback laser diode includes a first area having a first grating layer disposed in a longitudinal direction, a second area disposed adjacent to the first area and having a second grating layer disposed in the longitudinal direction, and an active layer disposed over the first and second areas. Coupling coefficients of the first and second grating layers are made different in the first and second areas by a selective area growth method. The distributed feedback laser diode includes grating layers each having an asymmetric coefficient and is implemented within an optimal range capable of obtaining both a high front facet output and stable single mode characteristics. Thus, high manufacturing yield and low manufacturing cost can be achieved.

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.

Abstract: Provided is a multi-wavelength optical source generator. The multi-wavelength optical source generator includes: a gain part generating a plurality of lights through a plurality of gain waveguides; a reflective part transmitting or reflecting lights provided from each of the plurality of gain waveguides according to a wavelength; and a multiplexing part multiplexing a plurality of lights transmitted and outputted through the reflective part.

Abstract: Provided is a bidirectional WDM-PON. The bidirectional WDM-PON includes an optical comb generator, an amplifier, an optical de-interleaver, a downstream signal generator, an upstream signal generator, an upper circulator, and a lower circulator. The optical comb generator generates multi-wavelength light. The amplifier amplifies the multi-wavelength light. The optical de-interleaver receives the amplified multi-wavelength light to divide the received light into an odd wavelength train and an even wavelength train, and outputs the odd and even wavelength trains. The downstream signal generator receives the odd wavelength train to generate a downstream signal. The upstream signal receiver receives an upstream signal. The upper circulator determines a delivery path of the odd wavelength train and the downstream signal. The lower circulator determines a delivery path of the even wavelength train and the upstream signal.

Abstract: Provided is an optical comb generator including a light source, a first waveguide region, a modulation region, and a second waveguide region. The light source is configured to output single-mode light. The first waveguide region divides an output of the light source into first light and second light. The modulation region includes a first modulator and a second modulator modulating the first light and the second light respectively. The second waveguide region combines outputs of the first modulator and the second modulator to output an optical comb. Here, the first modulator and the second modulator respectively include a first quantum well and a second quantum well having an asymmetric structure with respect to each other. The light source, the first waveguide region, the modulation region, and the second waveguide region are integrated into one substrate.

Abstract: Provided is an optical device. The optical device includes a multiplexer/demultiplexer, a multimode interference (MMI) coupler, a first waveguide, and second waveguides. The multiplexer/demultiplexer splits optical signals having a plurality of channels and received through a first port according to their wavelength to provide the split optical signals to second ports, or providing input optical signals having wavelengths difference from each other and received through the second ports to the first port. The multimode interference (MMI) coupler is connected to the first port. The first waveguide is connected to the MMI coupler. The second waveguides are connected to the second ports. The MMI coupler has a width decreasing toward the multiplexer/demultiplexer.

Abstract: Provided is a frequency-tunable terahertz light source device. The frequency-tunable terahertz light source device satisfies a Littrow diffraction condition at a wavelength and simultaneously satisfies a Littman-Metcalf diffraction condition at another wavelength using a double diffraction grating having two grating periods. Thus, oscillations simultaneously occur at the two different wavelengths, such that a terahertz wave can be stably generated by beating of the two oscillation wavelengths. In addition, the frequency-tunable terahertz light source device can readily change a frequency up to several terahertz and can be fabricated in a small size.

Abstract: Provided is an upstream source light generator of a passive optical network (PON) system. The upstream source light generator includes an amplification part configured to amplify injection light, and a reflection part configured to receive the amplified injection light and generate reflection light by reflecting the amplified injection light with different optical delays according to wavelengths of the amplified injection light.

Abstract: An optical interleaver of a wavelength division multiplexing (WDM) system includes an optical coupler, first and second waveguides, a high reflection mirror, and first and second phase shifters. The coupler divides an input optical signal. The first waveguide branches off from the coupler in a first direction. The second waveguide branches off from the coupler in a second direction for providing an optical path different from that provided by the first waveguide. The high reflection mirror is disposed at an end of the first waveguide for reflecting a first optical signal incident onto the first waveguide. The first phase shifter is disposed at an end of the second waveguide for multiple-reflecting a second optical signal incident onto the second waveguide. The second phase shifter is disposed at the first or second waveguide for adjusting an optical path difference between the first and second waveguides by varying its refractive index.