Viavi Solutions Inc.

Driss Touahri

Christopher Russell Wagner

Joshua Benjamin Julius Philipson

Luis Andre Neves Paiva Fernandes

Robert Matthew Adams

Elias Debs

Jeffery Stephen Graves

Darko Cugalj

A monochromator apparatus in a grating-based optical spectrum analyzer (OSA) includes a diffraction grating, a reflector element, and a tunable spectral filter. The tunable spectral filter may include a band-pass filter, a low-pass filter, a high-pass filter, or a linear variable filter, for example. A spectral window of the filter may move synchronously with the scanning spectral window of the OSA. A high-pass filter implementation may be introduced during a subsequent portion of the OSA window before the optical ghost signal starts appearing. The filter may either be linearly scanned across the optical beam, angularly tuned, or introduced in a subsequent portion of the OSA scanning window.

Elimination of optical ghosts in optical spectral analyzers through a scanning spectral filter

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.

Variable optical attenuator arrays

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.

Reducing polarization dependent loss (PDL) in a grating-based optical spectrum analyzer (OSA)

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.

Techniques for reducing optical ghosts in a gratings-based optical spectrum analyzer (OSA)

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.

High resolution multi-pass optical spectrum analyzer

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.

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Nepean, Canada

Driss Touahri