Techniques for WDM Mux/DeMux on cable and methods of making the same are described According to one aspect of the present application, a unit designed to provide multiplexing or demultiplexing (Mux/Demux) functions is implemented on cable. In other words, the Mux/Demux unit is coupled by a multi-fiber cable to a system (e.g., a system rack for router or switch that has multiple pluggable transceiver slots).

A wavelength-division multiplexing (WDM) optical assembly with increased lane density is disclosed herein. The WDM optical assembly includes a WDM optical core subassembly including an optical signal router for routing an optical signal between a first side and a second side of a substrate. The WDM optical core subassembly further includes a first WDM filter having a first passband and a second WDM filter having a second passband. The WDM optical core subassembly forms a first optical path between a first common port, the first WDM filter, and a first channel port, and to form a second optical path between the second WDM filter, a second common port, and a second channel port. The WDM optical core subassembly increases lane density while decreasing size and complexity by including a plurality of common ports in optical communication with the same plurality of WDM filters.

In various embodiments, free-space optical collimator and multi-channel wavelength division multiplexers including free-space optical collimators are provided. In one embodiment, for example, a free-space optical collimator includes a base having a length, a generally flat bottom surface and a top surface. A groove is disposed along the top surface of the base extending through the length of the base. A lens is disposed within the groove of the base and a fiber optic pigtail is disposed generally adjacent to a focal point of the lens. The lens and fiber optic pigtail are aligned within the groove to reduce an off-angle offset of an optical light signal propagating through the free-space optical collimator. In other embodiments, a process of producing a free-space optical collimator is also provided.

The filter transmits a light beam of a second wavelength emitted from each of a plurality of second light sources, reflects other light beams incident from a direction intersecting a traveling direction of the light beam of the second wavelength, and outputs a combined light of the light beam of the second wavelength and the other light beams. The first optical element transmits part of the light beam of the first wavelength emitted from the first light source or part of the light beam of the second wavelength included in the combined light output from the filter, and reflects the other light beams excluding the part thereof in the direction intersecting the traveling direction. The first light receiving element receives the part of the light beam of the first wavelength transmitted by the first optical element or the part of the light beam of the second wavelength.

Certain embodiments of the present disclosure are directed towards an optical assembly such as a wavelength multiplexers/demultiplexers (MDM). One example optical assembly generally includes: one or more wavelength filters configured to separate a plurality of wavelengths of an optical signal into respective optical signals; and a lens array comprising a first angled facet configured to reflect the optical signal to the one or more wavelength filters, wherein the lens array is configured to receive one or more of the respective optical signals from the one or more wavelength filters and focus the one or more of the respective optical signals before reaching an optical interface for a photonic chip.

A multi-channel receiver optical subassembly (ROSA) including at least one sidewall receptacle configured to receive and electrically isolate an adjacent multi-channel transmitter optical subassembly (TOSA) is disclosed. The multi-channel ROSA includes a housing with at least first and second sidewalls, with the first sidewall being opposite the second sidewall and including at least one sidewall opening configured to fixedly attach to photodiode assemblies. The second sidewall includes at least one sidewall receptacle configured to receive at least a portion of an optical component package, such as a transistor outline (TO) can laser package, of an adjacent multi-channel TOSA, and provide electrical isolation between the ROSA housing and the TOSA within an optical transceiver. The sidewall receptacle can include non-conductive material in regions that directly or otherwise come into close proximity with the optical component package of the adjacent TOSA.

The disclosed flow cytometer includes a wavelength division multiplexer (WDM). The WDM includes an extended light source providing light that forms an object, a collimating optical element that captures light from the extended light source and projects a magnified image of the object as a first light beam, and a first focusing optical element configured to focus the first light beam to a size smaller than the object of the extended light source to a first semiconductor detector. The disclosed flow cytometer further includes a composite microscope objective to direct light emitted by a particle in a flow channel in a viewing zone of the composite microscope to the extended light source, a fluidic system and a peristaltic pump configured to supply liquid sheath and liquid sample to the flow channel, and a laser diode system to illuminate the particle in the flow channel.

The disclosed flow cytometer includes a wavelength division multiplexer (WDM). The WDM includes an extended light source providing light that forms an object, a collimating optical element that captures light from the extended light source and projects a magnified image of the object as a first light beam, and a first focusing optical element configured to focus the first light beam to a size smaller than the object of the extended light source to a first semiconductor detector. The disclosed flow cytometer further includes a composite microscope objective to direct light emitted by a particle in a flow channel in a viewing zone of the composite microscope to the extended light source, a fluidic system and a peristaltic pump configured to supply liquid sheath and liquid sample to the flow channel, and a laser diode system to illuminate the particle in the flow channel.

Techniques are disclosed for providing relatively short distances between multi-channel transmitter optical subassemblies (TOSAs) and associated transmit connecting circuit in order to reduce losses due to signal propagation delays, also sometimes referred to as signal flight time delays. In an embodiment, a TOSA includes a plurality of laser assemblies disposed along a same sidewall of the TOSA along a longitudinal axis. The TOSA may be disposed within an optical transceiver housing in a transverse orientation, whereby a longitudinal center line of the multi-channel TOSA is substantially perpendicular to the longitudinal axis of the optical transceiver housing. The TOSA may be positioned adjacent an end of the optical transceiver housing having a transmit connecting circuit. Thus each of the plurality of laser assemblies may be positioned at a relatively short distance, e.g., 120 microns or less, away from the transmit connecting circuit.

Optical wavelength division multiplexing (WDM) devices include an optical chip having a number of waveguides therein, with a common optical fiber and single wavelength channel optical fibers optically coupled to the waveguides. Wavelength sensitive filters are disposed between the chip and the fibers, or across waveguides within the chip to reflect light at certain wavelengths and to transmit light at other wavelengths. In some embodiments, all of the fibers are located at the same end of the chip, in others the common fiber is located at one side of the chip and the single channel fibers located at another side, while in others the common fiber is located at a first side of the chip and the single channel fibers are located either at the first side of the chip or at a second side of the chip.