Abstract: A display device includes a pixel. The pixel is electrically connected to a first power line, a second power line, and a data line. The pixel includes a first transistor, and a capacitor electrically connected between a gate electrode of the first transistor and an electrode of the first transistor. In a plan view, the data line extends in a second direction. The first power line extends in a first direction intersecting the second direction and overlaps the data line and the gate electrode of the first transistor. The second power line extends in the second direction, overlaps the data line, and overlaps the gate electrode of the first transistor.

Abstract: In examples, provided are leadless power couplers that include (1) a thermal insulating system having an outer wall and an inner wall, (2) a first electrically conductive winding located outside the thermal insulating system, where the first electrically conductive winding is configured to create a varying magnetic field, (3) a plurality of second electrically conductive windings located inside the thermal insulating system and configured to couple to the varying magnetic field, the plurality of second electrically conductive windings being superconductors, (4) a plurality of cryogenic rectifiers, each cryogenic rectifier being coupled to a respective second electrically conductive winding in the plurality of second electrically conductive windings, and (5) a plurality of cryogenic cables coupled between respective outputs of the plurality of cryogenic rectifiers and respective loads.

Abstract: The present invention provides a method and an apparatus for monitoring optical signal to noise ratio (OSNR) in a wavelength division multiplexing optical transmission system. The present invention utilizes a polarization nulling method and a tunable optical bandpass filter in order to reliably monitor the OSNR by considering a finite polarization nulling ratio, polarization mode dispersion and non-linear birefringence of the optical system in real time measurement of the OSNR. Further, the tunable optical bandpass filter is controlled to filter all wavelength bands of wavelength division multiplexed signals. Since the invention may monitor a plurality of demultiplexed optical signals with a single apparatus, the overall cost of the OSNR monitoring equipment is significantly reduced.

Abstract: The present invention relates to a method and apparatus for automatically monitoring an optical signal-to-noise ratio in which an arbitrarily polarized optical signal including an unpolarized ASE noise is inputted to a rotating quarter-wave plate and then to a rotating linear polarizer so that a maximum power and a minimum power of the signal outputted from the rotating linear polarizer can be detected, and the detected maximum power and minimum power is used for automatically monitoring the optical signal-to-noise ratio.

Abstract: The present invention provides a method and an apparatus for monitoring optical signal to noise ratio (OSNR) in a wavelength division multiplexing optical transmission system. The present invention utilizes a polarization nulling method and a tunable optical bandpass filter in order to reliably monitor the OSNR by considering a finite polarization nulling ratio, polarization mode dispersion and non-linear birefringence of the optical system in real time measurement of the OSNR. Further, the tunable optical bandpass filter is controlled to filter all wavelength bands of wavelength division multiplexed signals. Since the invention may monitor a plurality of demultiplexed optical signals with a single apparatus, the overall cost of the OSNR monitoring equipment is significantly reduced.

Abstract: A bidirectional add/drop optical amplifier used in wavelength division multiplexing (WDM) optical networks to suppress the power change resulting from the adding and dropping of optical signals using an all optical gain control includes two fiber Bragg gratings (FBGs) and a bidirectional add/drop optical amplifier module composed of an Arrayed Waveguide Grating (AWG) and two bidirectional optical amplifiers. The filtered amplified spontaneous emission (ASE) lights are lased with the two FBGs and then used to adjust the gain of the bidirectional amplifiers.

Abstract: The present invention relates to a method and apparatus for automatically monitoring an optical signal-to-noise ratio in which an arbitrarily polarized optical signal including an unpolarized ASE noise is inputted to a rotating quarter-wave plate and then to a rotating linear polarizer so that a maximum power and a minimum power of the signal outputted from the rotating linear polarizer can be detected, and the detected maximum power and minimum power is used for automatically monitoring the optical signal-to-noise ratio.

Abstract: The present invention relates to a bidirectional add/drop optical amplifier used in wavelength division multiplexing (WDM) optical networks.

Abstract: This invention is to construct a bidirectional WDM add/drop amplifier module for transmitting WDMS in bidirection and for adding/dropping a signal in bidirection at each node in a WDM network system using a single N×N multiplexer. The bidirectional WDM add/drop amplifier module 100 comprises an 8×8 arrayed-waveguide grating 110. The 8×8 arrayed-waveguide grating 110 has, at each side, a WDMS input end L4 or R4, a WDMS output end L8 or R8, three separated signal input ends L1, L2 and L3, or R5, R6 and R7, and three separated signal output ends L5, L6 and L7, or R1, R2 and R3. One L2 or R6 of the separated signal input ends is designated as an added signal input end, one L6 or R2 of the separated signal output ends is designated as a dropped signal output end, and the separated signal output ends L5 and L7, or R1 and R3 except for the dropped signal output end connected to the signal input ends L1 and L3, or R5 and R7 at the same side.