Abstract:
A waveguide structure is provided. The waveguide structure includes: a slot channel waveguide including first and second patterns, which are spaced apart from each other to define a slot; a first upper layer covering at least a portion of the slot channel waveguide; and a second upper layer covering the remaining portion of the slot channel waveguide. A thermo-optic coefficient (TOC) of the channel waveguide times a TOC of the second upper layer is a negative number.
Abstract:
Provided are a waveguide structure and an arrayed waveguide grating structure. The arrayed waveguide grating structure includes an input star coupler, an output star coupler, and a plurality of arrayed waveguides optically connecting the input star coupler and the output star coupler. Each of the arrayed waveguides includes at least one section having a high confinement factor and at least two sections having a relatively low confinement factor. The sections of the arrayed waveguides having a high confinement factor have the same structure.
Abstract:
Provided are a waveguide structure and an arrayed waveguide grating structure. The arrayed waveguide grating structure includes an input star coupler, an output star coupler, and a plurality of arrayed waveguides optically connecting the input star coupler and the output star coupler. Each of the arrayed waveguides includes at least one section having a high confinement factor and at least two sections having a relatively low confinement factor. The sections of the arrayed waveguides having a high confinement factor have the same structure.
Abstract:
Provided are a flexible waveguide structure and an optical interconnection assembly. The flexible waveguide structure includes a thin film strip core, an inner cladding layer, and an outer cladding layer. The thin film strip core has opposed first and second surfaces and is formed of a metal. The inner cladding layer covers at least one of the first and second surfaces of the thin film strip core. The outer cladding layer covers the inner cladding layer. The inner cladding layer has a refractive index higher than that of the outer cladding layer.
Abstract:
A method for recognizing the step movement sequence of a control rod drive mechanism of a nuclear reactor, which withdraws and inserts a control rod of a nuclear reactor, includes the steps of: measuring current and voltage flowing through an electromagnetic coil used in the control rod drive mechanism of the nuclear reactor; calculating inductance of the coil by using the measured current and voltage; calculating a distance between a rotor and a stator of the control rod drive mechanism on the basis of the calculated inductance; and recognizing the step movement sequence of the control rod drive mechanism on the basis of the calculated distance. This method ensures good reliability in determining the step movement sequence, allows easy implementation using a digital signal processor, and is hardly affected by external factors such as noise.
Abstract:
A prepolymer prepared by condensation reaction between a first compound represented by Formula (1) below: Ar—H (1), where Ar is composed of a crosslinkable moiety at one end, a moiety selected from the group —O—, —S—, —COO—, —CO—, —COS—, —SO2—, and —NH—, and one or two repeating units selected from the group: where A is carbon or nitrogen, and X is hydrogen or halogen; and a second compound that is an aromatic moiety.
Abstract:
Provided are a light emitting device and an optical coupling module. The device includes a substrate, a light emitting part provided to the substrate, and a reflecting part provided to a lower surface of the substrate. The light emitting part includes an active pattern disposed on the substrate, an upper mirror provided to an upper portion of the active pattern, and a lower mirror provided to a lower portion of the active pattern. The light emitting part may emit light normal to the substrate, and the reflecting part may reflect the emitted light to a side surface of the substrate.
Abstract:
A method for recognizing the step movement sequence of a control rod drive mechanism of a nuclear reactor, which withdraws and inserts a control rod of a nuclear reactor, includes the steps of: measuring current and voltage flowing through an electromagnetic coil used in the control rod drive mechanism of the nuclear reactor; calculating inductance of the coil by using the measured current and voltage; calculating a distance between a rotor and a stator of the control rod drive mechanism on the basis of the calculated inductance; and recognizing the step movement sequence of the control rod drive mechanism on the basis of the calculated distance. This method ensures good reliability in determining the step movement sequence, allows easy implementation using a digital signal processor, and is hardly affected by external factors such as noise.
Abstract:
In a method for detecting a fault of a power module for a control system of a control rod drive mechanism of a nuclear reactor, a fault of the power module is separately detected in a “go” mode, a “hold” mode and a “double hold” mode of a control rod. In the “go” mode, fault is detected by comparing voltage ripples of a movable gripper coil, a stationary gripper coil and a lifting coil of the control rod drive mechanism. In the “hold” mode, fault is detected by means of power spectrum analysis at a predetermined frequency using a Discrete Fourier Transform (DFT) for a stationary gripper coil, and by means of a Root Means Square (RMS) calculation of coil voltage for a movable gripper coil. In the “double hold” mode, fault is detected using power spectrum analysis at a predetermined frequency using a DFT for both stationary and movable gripper coils.
Abstract:
Provided are a light emitting device and an optical coupling module. The device includes a substrate, a light emitting part provided to the substrate, and a reflecting part provided to a lower surface of the substrate. The light emitting part includes an active pattern disposed on the substrate, an upper mirror provided to an upper portion of the active pattern, and a lower mirror provided to a lower portion of the active pattern. The light emitting part may emit light normal to the substrate, and the reflecting part may reflect the emitted light to a side surface of the substrate.