A tunable optical filter integrates the functions of wavelength tuning and power isolation of back reflection. The optical signal enters a Faraday rotator twice, and isolation is provided by two birefringent crystals, having their optical axes oriented at 45 degrees with respect to each other. The two birefringent crystals are on the same side of the Faraday rotator. The integration of an optical tunable filter and an isolator function into a single packaged component helps to reduce the size and complexity of optical amplifier systems, such as EDFAs and PDFAs, operating in the 1550 nm and 1310 nm transmission bands, respectively.

A system can include a splitter configured to receive a first optical signal carrying first data and generate a first optical signal copy and second optical signal copy. Also included is at least one optical processing path includes at least one optical encoder configured to transform the first optical signal copy into a second optical signal carrying the first data and an additional optical feature not present in the first optical signal, at least one optical modulator configured to optically modulate the second optical signal according to a compare data to generate an optical match signal that indicates matches between the compare data and the first data, and at least one photodetector configured to generate an electrical match signal in response to the optical match signal. Corresponding methods are also disclosed.

A light source optical system includes: a first optical system configured to guide a first light beam having a first wavelength emitted from a light source to a wavelength conversion element; the wavelength conversion element configured to convert the first light beam into a second light beam having a second wavelength different from the first wavelength, and emit the second light beam; and a second optical system through which the second light beam emitted from the light conversion element passes. The second optical system includes a light guide element configured to guide a portion of the second light beam from one end surface of the light guide element to the other end surface of the light guide element to separate the portion of the second light beam from the second light beam.

A photonic platform based polarization controller providing a fixed target polarization is disclosed. The polarization controller has a polarization rotator splitter splitting the beam into first and second feeds corresponding to first and second orthogonal polarization components. A first Mach-Zehnder interferometer (MZI) stage provides a first phase delay between the first and second feeds based on a first control signal, and a first mixer mixes the first and second feeds to provide third and fourth feeds. A second MZI stage provides a second phase delay between the third and fourth feeds based on a second control signal, and a second mixer mixes the third and fourth feeds to provide fifth and sixth feeds. A third MZI stage provides a third phase delay between the fifth and sixth feeds based on a third control signal, and a third mixer mixes the fifth and sixth feeds to provide the fixed target polarization. An optical tap splits a portion of the beam.

A micro-ring resonator includes: at least one first straight waveguide; a second waveguide (Arm3) and a third waveguide (Arm2), where the second waveguide (Arm3) and the third waveguide (Arm2) form a closed annular waveguide, and the annular waveguide is coupled to the first waveguide; a fourth waveguide (Arm1), where the fourth waveguide (Arm1) is coupled to the annular waveguide; and a polarization splitter (PS), where one end of the polarization splitter (PS) is connected to the fourth waveguide (Arm1), and one end is connected to the second waveguide (Arm3) in the annular waveguide. In the micro-ring resonator, a distance between two waveguides for separately transmitting different polarized light breaks a limitation of a resonator radius, and further, a distance between a TE path and a TM path is reduced.

A photonic integrated circuit comprises an input interface adapted for receiving an optical input signal and splitting it into two distinct polarization modes and furthermore adapted for rotating the polarization of one of the modes for providing the splitted signals in a common polarization mode. The PIC also comprises a combiner adapted for combining the first mode signal and the second mode signal into a combined signal and a decohering means adapted for transforming at least one of the first mode signal and the second mode signal such that the first mode signal and the second mode signal are received by the combiner in a mutually incoherent state. A processing component for receiving and processing said combined signal is also comprised.

A single-fiber bidirectional optical transceiver module of the same wavelength. A sub-wavelength grating and a Faraday rotator are used, and the same element is reused to implement a polarization multiplex/de-multiplex function, so as to implement transmission and receiving of an optical signal in a small space. The single-fiber bidirectional optical transceiver module has less optical elements, a compact structure, and low cost, meeting the needs on a miniaturized, integrated, and high speed optical transceiver module for a modern optical communication system.

There is provided a light-guide, compact collimating optical device, including a light-guide having a light-waves entrance surface, a light-waves exit surface and a plurality of external surfaces, a light-waves reflecting surface carried by the light-guide at one of the external surfaces, two retardation plates carried by light-guides on a portion of the external surfaces, a light-waves polarizing beamsplitter disposed at an angle to one of the light-waves entrance or exit surfaces, and a light-waves collimating component covering a portion of one of the retardation plates. A system including the optical device and a substrate, is also provided.

A noise reduction device capable of reducing noise over a wide frequency range and a detection apparatus including the same are provided. The noise reduction device includes a splitting unit configured to split pulsed light generated in a first period into three or more pulsed light beams, a delaying unit configured to provide the three or more pulsed light beams with different delay times, and a combining unit configured to combine the three or more pulsed light beams. Among the three or more pulsed light beams, two pulsed light beams whose delay times provided by the delaying unit are closest to each other are configured such that a difference between their delay times is equal to the first period.

A polarization splitter and rotator device includes an optical mode converter comprising a first optical waveguide, wherein a core of the first optical waveguide is asymmetrically shaped; and an output coupler comprising a second optical waveguide coupled to the first optical waveguide and a third optical waveguide adiabatically coupled to the second optical waveguide, the adiabatically coupling provoking the polarized light coupled from the first optical waveguide into the second optical waveguide to spread its power between the second optical waveguide and the third optical waveguide by coupling its transverse electric mode of first order as transverse electric mode of zeroth order into the third optical waveguide and keeping its transverse electric mode of zeroth order propagating in the second optical waveguide without coupling to the third optical waveguide.