Provided is a photoelectric detector, comprising: a silicon layer (110), the silicon layer (110) comprising a first-doping-type doped region (111); a germanium layer (120) in contact with the silicon layer (110), the germanium layer (120) comprising a second-doping-type doped region (121); and a silicon nitride waveguide (130), the silicon nitride waveguide (130) being arranged surrounding the germanium layer (120) along the extension directions of at least three side walls of the germanium layer (120), wherein the silicon nitride waveguide (130) is used for transmitting an optical signal and coupling the optical signal to the germanium layer (120), and the germanium layer (120) is used for detecting the optical signal and converting the optical signal into an electrical signal.

A split waveguide filter is described. The split waveguide filter includes a first waveguide section having a first outer surface and a first inner surface and a second waveguide section having a second outer surface and a second inner surface. When the first waveguide section and the second waveguide section are mated together, the first inner surface and the second inner surface form a waveguide aperture. The split waveguide filter also includes a first collar clamp for securing a first portion of the mated first waveguide section and second waveguide section together; and a second collar clamp for securing a second portion of the mated first waveguide section and second waveguide section together.

A device for combining several light beams, the device including several hollow input waveguides, at least one per light beam, as well as a hollow output waveguide which is the same for the different light beams, each input waveguide having an input opening to let the corresponding light beam enter, and, at the opposite, an output opening through which it emerges in the output waveguide, the output waveguide, as well as each input waveguide being laterally delimited by one or more metallic reflecting surfaces, and wherein at least a section of the output waveguide is divergent and widens in the direction of an output opening of the output waveguide.

A light guide includes: a light guide board configured to allow light incident on an optical entrance to propagate through the light guide board, the light guide board including: the optical entrance; a first face; and at least one partial reflection layer within the light guide board and tilted to the first face. The at least one partial reflection layer is configured to reflect a part of light incident on the at least one partial reflection layer at an incident angle of greater than or equal to a critical angle θ.sub.r to allow the reflected light to exit the light guide board through the first surface while transmitting therethrough a remainder of the light incident on the at least one partial reflection layer. Formula below is satisfied: θ.sub.r=sin.sup.−1(n.sub.2/n.sub.1) where θ.sub.r is the critical angle; n.sub.1 is a refractive index of the light guide board; and n.sub.2 is a refractive index of the at least one partial reflection layer.

A light guide includes: a light guide board configured to allow light incident on an optical entrance to propagate through the light guide board, the light guide board including: the optical entrance; a first face; and at least one partial reflection layer within the light guide board and tilted to the first face. The at least one partial reflection layer is configured to reflect a part of light incident on the at least one partial reflection layer at an incident angle of greater than or equal to a critical angle θ.sub.r to allow the reflected light to exit the light guide board through the first surface while transmitting therethrough a remainder of the light incident on the at least one partial reflection layer. Formula below is satisfied: θ.sub.r=sin.sup.−1(n.sub.2/n.sub.1) where θ.sub.r is the critical angle; n.sub.1 is a refractive index of the light guide board; and n.sub.2 is a refractive index of the at least one partial reflection layer.

A fiber optic test device is provided that includes a light source pigtailed with a first end of a non-bend insensitive multimode fiber (non-BIMMF). A second end of the non-BIMMF is fusion spliced to a first end of a reference grade bend insensitive multimode fiber (BIMMF). A reference grade optical fiber connector is attached to a second end of the BIMMF, which is coupled to a first end of a reference grade bulkhead adapter. The non-BIMMF is deformed so that a specific launch condition, such as encircled flux, is achieved at the first end of the BIMMF. A test reference cord, which contains a reference grade BIMMF having similar geometric properties as the BIMMF that is fusion spliced to the non-BIMMF, is attached to a second end of the bulkhead adapter. Modal transparency is achieved and the launch condition is maintained at the output of the test reference cord.

A system includes a housing including a front panel, a rear panel, an upper panel, and a lower panel. The system includes a first circuit board or substrate, at least one data processor coupled to the first circuit board or substrate and configured to process data, and at least one optical module coupled to the first circuit board or substrate. Each optical module is configured to perform at least one of (i) convert input optical signals to electrical signals that are provided to the at least one data processor, or (ii) convert electrical signals received from the at least one data processor to output optical signals. The system includes at least one inlet fan mounted near the front panel and configured to increase an air flow across a surface of at least one of (i) the at least one data processor, (ii) a heat dissipating device thermally coupled to the at least one data processor, (iii) the at least one optical module, or (iv) a heat dissipating device thermally coupled to the at least one optical module. The system includes at least one laser module configured to provide optical power to the at least one optical module.

An optical receptacle includes a first optical surface, a second optical surface, and an annular first cylindrical part disposed to surround a second central axis of the second optical surface. The first cylindrical part includes a first inner surface with a circular shape in a cross section perpendicular to the second central axis, and a second inner surface disposed on a second optical surface side than the first inner surface and provided with a circular shape in the cross section perpendicular to the second central axis. A diameter of the first inner surface is greater than a diameter of the second inner surface, and a length of the second inner surface in a direction along the second central axis is 0.5 to 4.0 mm.

A photonic structure is provided. The photonic structure includes a guiding region, a sensing region, and logic region. The guiding region has a first side and a second side opposite to the first side. The sensing region is disposed on the second side of the guiding region. The logic region is disposed on a side of the sensing region opposite to the guiding region. The guiding region, the sensing region, and the logic region are stacked along a vertical direction. A method for manufacturing the photonic structure is also provided.

An apparatus and method herein efficiently couple spatial light to optical fiber light for achieving stability of an optical axis without a position sensor. The basic concept of the method includes: first, obtaining, according to a theoretical coupling efficiency model, a model parameter by means of fitting calculation; second, using a four-point tracking algorithm to calculate an optical fiber nutation trajectory according to the optical fiber nutation principle; and finally, using the nutation trajectory to calculate the position deviation of a central point. The optical axis is ensured to be stable by correcting the position deviation, and the high coupling efficiency remains. The method is used for the stability of the optical axis in a space coherent laser communication DPSK link. The high efficiency coupling is a key technology of long-distance, high bit rate transmission in space laser communication, and is significant in the development of inter-satellite optical communications.