Abstract:
Provided is a germanium photodetector having a germanium epitaxial layer formed without using a buffer layer and a method of fabricating the same. In the method, an amorphous germanium layer is formed on a substrate. The amorphous germanium layer is heated up to a high temperature to form a crystallized germanium layer. A germanium epitaxial layer is formed on the crystallized germanium layer.
Abstract:
Provided is a high-speed ring optical modulator based on a silicon semiconductor, having increased optical modulation speed. The high-speed ring optical modulator includes a ring optical waveguide including a portion in which the refractive index varies, that is, a refractive index variation portion, and an optical waveguide having a constant refractive index. The refractive index variation portion comprises a bipolar transistor. Thus carriers can be supplied to and discharged from the refractive index variation portion, through which light is transmitted, at high speed, and thus the optical modulation speed can be increased.
Abstract:
Provided is an optical device with improved phase shift and propagation loss of light without decreasing the dynamic characteristics of the optical device. The optical device includes a first semiconductor layer which is doped with a first type of conductive impurities and has a uniform thickness; a gate insulating layer which has a ? shape and is formed on a portion of the first semiconductor layer and has a thin center portion; and a second semiconductor layer which covers an upper surface of the gate insulating layer and is doped with a second type of conductive impurities opposite to the first type of conductive type impurities.
Abstract:
A current-jump-control circuit including an abrupt metal-insulator phase transition device is proposed, and includes a source, the abrupt metal-insulator phase transition device and a resistive element. The abrupt metal-insulator phase transition device includes first and second electrodes connected to the source, and shows an abrupt metal-insulator phase transition characteristic of a current jump when an electric field is applied between the first electrode and the second electrode. The resistive element is connected between the source and the abrupt metal-insulator phase transition device to control a jump current flowing through the abrupt metal-insulator phase transition device. According to the above current control circuit, the abrupt metal-insulator phase transition device can be prevented from being failed due to a large amount of current and thus the current-jump-control circuit can be applied in various application fields.
Abstract:
Methods of forming photo detectors are provided. The method includes providing a semiconductor layer on a substrate, forming a trench in the semiconductor layer, forming a first single crystalline layer and a second single crystalline layer using a selective single crystalline growth process in the trench, and patterning the first and second single crystalline layers and the semiconductor layer to form a first single crystalline pattern, a second single crystalline pattern and an optical waveguide.
Abstract:
Provided are a photonics chip and an optical apparatus including the same. The chip may include a substrate, an optical waveguide, an optical coupler, and a plurality of alignment units. The optical waveguide is formed on the substrate. The optical coupler is formed at the optical waveguide. The alignment units align an optical connector which fixes at least one optical fiber coupled to the optical coupler, on the substrate.
Abstract:
Provided are optical coupling devices and silicon photonics chips having the same. the optical coupling device may include a lower layer having a first region and a second region, a first core layer disposed on the lower layer, the first core layer including first and second waveguides disposed on the first and second regions, respectively, a clad layer covering the first waveguide, and a second core layer interposed between the clad layer and the lower layer to cover the second waveguide. The second waveguide has a width decreasing with increasing distance from the first region and a vertical thickness greater than that of the first waveguide.
Abstract:
Provided are light detection devices and methods of manufacturing the same. The light detection device includes a first conductive pattern on a surface of a substrate, an insulating pattern on the substrate and having an opening exposing at least a portion of the first conductive pattern, a light absorbing layer filling the opening of the insulating pattern and having a top surface disposed at a level substantially higher than a top surface of the insulating pattern, a second conductive pattern on the light absorbing layer, and connecting terminals electrically connected to the first and second conductive patterns, respectively.
Abstract:
An absorption modulator is provided. The absorption modulator includes a substrate, an insulation layer disposed on the substrate, and a waveguide having a P-I-N diode structure on the insulation layer. Absorptance of an intrinsic region in the P-I-N diode structure is varied when modulating light inputted to the waveguide. The absorption modulator obtains the improved characteristics, such as high speed, low power consumption, and small size, because it greatly reduces the cross-sectional area of the P-I-N diode structure.
Abstract:
Provided are an electro-optic device with a high modulation rate and a mach-zehnder optical modulator having the same. The electro-optic device includes a slap, a rip waveguide, a first impurity region, a second impurity region, and a third impurity region. The slap is disposed on a substrate. The rip waveguide includes a mesa extending in one direction on the slap and the slap disposed under the mesa. The first impurity region is disposed in the slap of one side of the mesa. The third impurity region is disposed in the slap of the other side of the mesa to oppose the first impurity region. The second impurity region is disposed in the rip waveguide between the first impurity region and the third impurity region.