Abstract: A system for a high resolution optical spectrum analyzer (OSA) using various optical configurations to reduce polarization dependent loss (PDL) is disclosed. The system may include a birefringent element to receive an input optical beam. The birefringent element may then split the optical beam into at least two exit beams. The system may also include an optical configuration comprising at least one optical element. The optical configuration may receive the at least two exit beams from the birefringent element and transform at least one of the two exit beams using the at least one optical element to provide two parallel beams with parallel polarizations. The optical configuration may then output the two parallel beams with parallel polarizations to a downstream optical element, such as a diffraction grating, or other optical element.

Abstract: A variable optical attenuator (VOA) may include an input collimator with an input fiber connected on one side and an output collimator with an output fiber connected on one side, where the collimators are on a same surface of a VOA enclosure. A retroreflector may receive a light beam from the input collimator and reflect the light beam to the output collimator. The VOA may include an attenuation element positioned between the input collimator and the retroreflector and/or another attenuation element positioned between the retroreflector and the output collimator to provide variable attenuation to the light beam. The attenuation elements may be moved to set an attenuation level by one or more adjustment elements such as a miniature motor. The attenuation element may include a gradient index (GRIN) element, a polarizer, a neutral density filter, or a wavelength tunable filter.

Abstract: A polarization scrambler using a retardance element (RE) is disclosed. The polarization scrambler may include an optical fiber input to transmit an optical signal, and a beam expander to receive and expand the optical signal to create an expanded optical signal. The polarization scrambler may include a retardance element (RE) to cause a polarization scrambling effect on the expanded optical signal and to create a scrambled expanded optical signal. The polarization scrambler may include a beam reducer to receive and reduce the scrambled expanded optical signal to create a scrambled optical signal. The polarization scrambler may include an optical fiber output to receive scrambled optical signal. The optical fiber output may transmit the scrambled optical signal to one or more downstream optical components.

Abstract: A system for a high resolution optical spectrum analyzer (OSA) using various optical configurations to reduce polarization dependent loss (PDL) is disclosed. The system may include a birefringent element to receive an input optical beam. The birefringent element may then split the optical beam into at least two exit beams. The system may also include an optical configuration comprising at least one optical element. The optical configuration may receive the at least two exit beams from the birefringent element and transform at least one of the two exit beams using the at least one optical element to provide two parallel beams with parallel polarizations. The optical configuration may then output the two parallel beams with parallel polarizations to a downstream optical element, such as a diffraction grating, or other optical element.

Abstract: A monochromator apparatus for an optical spectrum analyzer may include a diffraction grating, a rotatable oblique prism reflector element with a non-right-angle apex angle, and a mirror. An input optical beam received from an input component may be diffracted by the grating element and reflected by a reflector element, where the reflector element may include a rotatable oblique prism with an apex angle that is different from a right angle. A mirror may reflect the reflected diffracted optical beam back to the reflector element and the grating element. An output optical beam from the grating element may be provided via an output element to a detection element for high resolution optical measurement. The oblique prism reflector element may reduce or eliminate a Littrow ghost effect or secondary ghost effects caused by the grating element.

Abstract: A system for amplification of optical signals for optical measurement instrumentation is disclosed. The system may include a first logarithmic amplifier circuit in a first amplification path, and a linear amplifier circuit and a second logarithmic amplifier circuit coupled in series in a second amplification path. The first and second amplification paths may receive an input signal from a photodiode and provide amplified signals, in parallel, to a selection circuit, which may select one of the outputs of the first and second amplification paths based on one or two power thresholds. The selection circuit may then provide the selected output to a measurement circuit or device. In some examples, the system may also include a sampling circuit to sample the outputs and an analog-digital conversion circuit to digitize the outputs before selection. The power threshold(s) may be determined based on a saturation level of the linear amplifier circuit.

Abstract: A polarization scrambler using a retardance element (RE) is disclosed. The polarization scrambler may include an optical fiber input to transmit an optical signal, and a beam expander to receive and expand the optical signal to create an expanded optical signal. The polarization scrambler may include a retardance element (RE) to cause a polarization scrambling effect on the expanded optical signal and to create a scrambled expanded optical signal. The polarization scrambler may include a beam reducer to receive and reduce the scrambled expanded optical signal to create a scrambled optical signal. The polarization to scrambler may include an optical fiber output to receive scrambled optical signal. The optical fiber output may transmit the scrambled optical signal to one or more downstream optical components.

Abstract: A system for a high resolution optical spectrum analyzer (OSA) using an efficient multi-pass configuration is disclosed. The system may include an entrance slit to allow inward passage of an optical beam. The system may also include a grating element to diffract the optical beam. The system may further include a retroreflective element to retroreflect the optical beam. The system may also include a mirror to reflect the optical beam. The system may include an exit slit, which in some examples may be adjacent to the entrance slit. The exit slit may allow outward passage of the optical beam for a high resolution optical measurement.

Abstract: A polarization scrambler using a retardance element (RE) is disclosed. The polarization scrambler may include an optical fiber input to transmit an optical signal, and a beam expander to receive and expand the optical signal to create an expanded optical signal. The polarization scrambler may include a retardance element (RE) to cause a polarization scrambling effect on the expanded optical signal and to create a scrambled expanded optical signal. The polarization scrambler may include a beam reducer to receive and reduce the scrambled expanded optical signal to create a scrambled optical signal. The polarization to scrambler may include an optical fiber output to receive scrambled optical signal. The optical fiber output may transmit the scrambled optical signal to one or more downstream optical components.

Abstract: A system for providing optical measurements and detection in optical spectrum analyzers (OSAs) with high dynamic range and high speed is disclosed. The system may include a slit to allow inward passage of an optical beam. The system may also include an optical portion to receive the optical beam. In some examples, the optical portion may include at least one optical splitter to split the optical beam into at least two optical paths. The system may also include an electrical portion to receive the optical beams split into the at least two optical paths. In some examples, the electrical portion may include at least one photodetector to receive each of the split optical beam. The electrical portion may also include at least one amplifier communicatively coupled to each of the at least one photodetector to amplify the split optical beam.

Abstract: A polarization scrambler using a retardance element (RE) is disclosed. The polarization scrambler may include an optical fiber input to transmit an optical signal, and a beam expander to receive and expand the optical signal to create an expanded optical signal. The polarization scrambler may include a retardance element (RE) to cause a polarization scrambling effect on the expanded optical signal and to create a scrambled expanded optical signal. The polarization scrambler may include a beam reducer to receive and reduce the scrambled expanded optical signal to create a scrambled optical signal. The polarization scrambler may include an optical fiber output to receive scrambled optical signal. The optical fiber output may transmit the scrambled optical signal to one or more downstream optical components.

Abstract: A system for a high resolution optical spectrum analyzer (OSA) using various optical configurations to reduce polarization dependent loss (PDL) is disclosed. The system may include a birefringent element to receive an input optical beam. The birefringent element may then split the input optical beam into a first optical beam and a second optical beam. The system may also include an optical configuration, which may determine an optical beam path associated with the first optical beam and the second optical beam, transmit the first optical beam in a first direction along the optical beam path and transmit the second optical beam in a second direction along the optical beam path.

Abstract: According to examples, a system for measuring polarization dependent loss (PDL) for a device-under-test (DUT) may include a tunable laser, a polarization element and a power meter. The tunable laser may emit an optical signal to sweep across an optical band at a constant rate. The polarization element may scramble polarizations states of the optical signal emitted from the tunable laser. The power meter may take power measurements associated with the optical signal emitted from the tunable laser, wherein the power measurements from the power meter are used to determine a maximum insertion loss (IL) and a minimum insertion loss (IL) associated with the device-under-test (DUT). An average insertion loss (IL) and a polarization dependent loss (PDL) for the device-under-test (DUT) may be calculated based on the maximum insertion loss (IL) and the minimum insertion loss (IL) associated with the device-under-test (DUT).

Abstract: A system for a high resolution optical spectrum analyzer (OSA) using various optical configurations to reduce polarization dependent loss (PDL) is disclosed. The system may include a birefringent element to receive an input optical beam. The birefringent element may then split the optical beam into at least two exit beams. The system may also include an optical configuration comprising at least one optical element. The optical configuration may receive the at least two exit beams from the birefringent element and transform at least one of the two exit beams using the at least one optical element to provide two parallel beams with parallel polarizations. The optical configuration may then output the two parallel beams with parallel polarizations to a downstream optical element, such as a diffraction grating, or other optical element.

Abstract: An apparatus for providing an improved coupling link with integrated beam blocking and a bearing assembly using an axial preloading technique is disclosed. The apparatus may include a coupling link comprising a first end, a second end, and a middle section. The middle section may be connectable to a beam blocking element. The first end may include a first bearing assembly and may be connectable to a motor drive arm. The second end may include a second bearing assembly and may be connectable to an optical-mechanical element. In some examples, the apparatus may be used in various optical measurement and testing applications and environments. In some examples, the improved coupling link may also utilize an axial preloading technique to minimize excessive movement in bearings assemblies.

Abstract: A system for providing optical measurements and detection in optical spectrum analyzers (OSAs) with high dynamic range and high speed is disclosed. The system may include a slit to allow inward passage of an optical beam. The system may also include an optical portion to receive the optical beam. In some examples, the optical portion may include at least one optical splitter to split the optical beam into at least two optical paths. The system may also include an electrical portion to receive the optical beams split into the at least two optical paths. In some examples, the electrical portion may include at least one photodetector to receive each of the split optical beam. The electrical portion may also include at least one amplifier communicatively coupled to each of the at least one photodetector to amplify the split optical beam.

Abstract: An apparatus for providing an improved coupling link with integrated beam blocking and a bearing assembly using an axial preloading technique is disclosed. The apparatus may include a coupling link comprising a first end, a second end, and a middle section. The middle section may be connectable to a beam blocking element. The first end may include a first bearing assembly and may be connectable to a motor drive arm. The second end may include a second bearing assembly and may be connectable to an optical-mechanical element. In some examples, the apparatus may be used in various optical measurement and testing applications and environments. In some examples, the improved coupling link may also utilize an axial preloading technique to minimize excessive movement in bearings assemblies.

Abstract: A system for a high resolution optical spectrum analyzer (OSA) using an efficient multi-pass configuration is disclosed. The system may include an entrance slit to allow inward passage of an optical beam. The system may also include a grating element to diffract the optical beam. The system may further include a retroreflective element to retroreflect the optical beam. The system may also include a mirror to reflect the optical beam. The system may include an exit slit, which in some examples may be adjacent to the entrance slit. The exit slit may allow outward passage of the optical beam for a high resolution optical measurement.

Abstract: A system for providing optical measurements and detection in optical spectrum analyzers (OSAs) with high dynamic range and high speed is disclosed. The system may include a slit to allow inward passage of an optical beam. The system may also include an optical portion to receive the optical beam. In some examples, the optical portion may include at least one optical splitter to split the optical beam into at least two optical paths. The system may also include an electrical portion to receive the optical beams split into the at least two optical paths. In some examples, the electrical portion may include at least one photodetector to receive each of the split optical beam. The electrical portion may also include at least one amplifier communicatively coupled to each of the at least one photodetector to amplify the split optical beam.

Abstract: A Faraday-based polarization scrambler is disclosed. The Faraday-based polarization scrambler may comprise a first toroidal assembly. The first toroidal assembly may include an optical fiber that is looped to form a first looped portion, and a first electrical wire that coils around the first looped portion to form a first toroidal configuration. In some examples, the first electrical wire may be connected to a voltage source and carries a current to form a magnetic field within the first toroidal configuration. In some examples, there may be additional toroidal assemblies provided to the Faraday-based polarization scrambler. One or more of these toroidal assemblies may create an actuation field to effect modulation for polarization scrambling and emulation that mitigates polarization-dependent effects.