Abstract: Disclosed herein are a material layer stack, a light emitting element, a light emitting package, and a method of fabricating a light emitting element. The material layer stack includes: a substrate having a first lattice constant; and a semiconductor layer grown on the substrate, the semiconductor layer having a second lattice constant that is different from the first lattice constant. Using the material layer stack, a light emitting element having a low leakage current, a low operation voltage, and an excellent luminous efficiency can be obtained.

Abstract: Disclosed herein are a material layer stack, a light emitting element, a light emitting package, and a method of fabricating a light emitting element. The material layer stack includes: a substrate having a first lattice constant; and a semiconductor layer grown on the substrate, the semiconductor layer having a second lattice constant that is different from the first lattice constant. Using the material layer stack, a light emitting element having a low leakage current, a low operation voltage, and an excellent luminous efficiency can be obtained.

Abstract: A method of manufacturing a light emitting diode (LED) includes forming a first material layer on a substrate, forming a second material layer on the first material layer, forming a photomask pattern on the second material layer, performing a first etching on the second material layer and a portion of the first material layer by using the photomask pattern as an etch mask, removing the photomask pattern, and forming a plurality of isolated structures by performing a second etching on the remaining portion of the first material layer until a top surface of the substrate is exposed.

Abstract: Provided is a semiconductor laser device including: a gain area where multi-wavelength lights are generated and gain are provided; a first reflection area where among the multi-wavelength lights, a first-wavelength light is reflected to the gain area in response to a first selection signal; a second reflection area where among the multi-wavelength lights, a second-wavelength light is reflected to the gain area; and a phase control area where a phase of the second-wavelength light is shifted in response to a phase control signal, the phase control area being disposed between the first reflection layer and the second reflection layer.

Abstract: A waveguide PIN photodiode is provided. The waveguide PIN photodiode includes a lower light guide layer, a light absorption layer, an upper light guide layer, and a cladding layer. The lower light guide is formed on a substrate, and the light absorption layer is formed on the lower light guide layer. The upper light guide layer is formed on the light absorption layer, and the cladding layer is formed on the upper light guide layer. The lower light guide layer, the light absorption layer, and the upper light guide layer constitute a core layer, which is an optical waveguide, and graded index distribution is symmetrically formed in a depth direction, centering around the light absorption layer having a highest refractive index.

Abstract: Disclosed is a high speed optical signal processor which includes a saturable absorber area including a substrate, an active layer, a clad layer and a first upper electrode which are sequentially formed on one face of the substrate, and a first lower electrode formed on the other face of the substrate; and a gain-clamped optical amplifier area including a substrate having a diffraction grating for generating a laser beam, an active layer, a clad layer and a second upper electrode which are sequentially formed on one face of the substrate, and a second lower electrode formed on the other face of the substrate, the second upper electrode being isolated from the first upper electrode of the saturable absorber area.

Abstract: Disclosed is a high frequency optical pulse source generating stable optical pulses over a wide current range in an optical transmission system to enhance stability and reliability, the high frequency optical pulse source implementing, in one chip, a multi-section distributed feedback (DFB) laser diode with a phase control section arranged between two DFB laser diodes. By controlling the current applied to the electrode of the phase control section while applying currents to the first and second DFB sections, the present invention causes self-mode locking between the compound-cavity modes having similar threshold currents, thereby generating stable tens GHz-level optical pulses. Hence, the present invention generates optical pulses uniformly over a wide current range, thereby enhancing the stability and reliability of the element.

Abstract: Disclosed is a high frequency optical pulse source generating stable optical pulses over a wide current range in an optical transmission system to enhance stability and reliability, the high frequency optical pulse source implementing, in one chip, a multi-section distributed feedback (DFB) laser diode with a phase control section arranged between two DFB laser diodes. By controlling the current applied to the electrode of the phase control section while applying currents to the first and second DFB sections, the present invention causes self-mode locking between the compound-cavity modes having similar threshold currents, thereby generating stable tens GHz-level optical pulses. Hence, the present invention generates optical pulses uniformly over a wide current range, thereby enhancing the stability and reliability of the element.

Abstract: Disclosed is a high speed optical signal processor which includes a saturable absorber area including a substrate, an active layer, a clad layer and a first upper electrode which are sequentially formed on one face of the substrate, and a first lower electrode formed on the other face of the substrate; and a gain-clamped optical amplifier area including a substrate having a diffraction grating for generating a laser beam, an active layer, a clad layer and a second upper electrode which are sequentially formed on one face of the substrate, and a second lower electrode formed on the other face of the substrate, the second upper electrode being isolated from the first upper electrode of the saturable absorber area.