A multi-channel wavelength division multiplexing/demultiplexing device includes optical filters for respective optical channels, and at least one microlens. The optical filters guide a light beam to travel along a preset optical path, and each optical filter filters a specific and different range of wavelength, and has a first surface for incident and reflective light, and a second surface for outgoing light through penetration as an output beam for the corresponding channel. Each microlens is installed between two adjacent optical filters to adjust optical beam shape of the traveling light along the optical path, particularly, altering a beam waist of a Gaussian beam and an imaging position to greatly increase optical efficiency of collimators for the whole system.

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.

There are provided: a plurality of optical elements for handling light having different wavelengths; a plurality of collimating lenses individually provided in the optical elements, each of the collimating lenses having a first end facing a main surface of one of the optical elements; an optical multi-demultiplexer using reflection of light caused by a spatial optical system, the optical multi-demultiplexer having a first end facing a second end of each of the collimating lenses; a coupling lens having a first end facing a second end of the optical multi-demultiplexer; an SMF having one end facing a second end of the coupling lens; and an optical block, which is transparent, provided on an optical path between each of the collimating lenses and the optical multi-demultiplexer, the optical path having a small number of reflections in the optical multi-demultiplexer.

Method and multiport free-space wavelength division multiplexing (“WDM”) device capable of handling multiple optical signals carried in multiple wavelengths (“λ.sub.n”) using a relay lens are disclosed. The WDM device includes an optical filter, collimator, optical relay, and a relay optical filter. The optical filter is able to receive an optical beam containing multiple λ.sub.n and subsequently extract a first wavelength (“λ.sub.1”) from λ.sub.n. A second optical beam is formed by the remaining of λ.sub.n. The collimator, in one example, receives λ.sub.1 from the optical filter. Upon receiving the second optical beam, the optical relay collimates the second optical beam with minimal loss due to light divergence. The relay optical filter, in one aspect, is configured to receive the collimated second optical beam and redirects the collimated second optical beam to a predefined intended orientation.

An optical add/drop device (100) comprising: a common port (102); an add port (106); a first wavelength selective optical filter (110) configured to: receive an optical signal at an add wavelength from the add port and transmit said optical signal at the add wavelength towards the common port; and receive optical signals from the common port and reflect optical signals not at the add wavelength; a second wavelength selective optical filter (114) configured to receive said optical signals from the common port reflected by the first wavelength selective optical filter and transmit an optical signal at a drop wavelength, different to the add wavelength; a drop port (116); and an optical waveguide (118) configured receive said optical signal at the drop wavelength transmitted by the second wavelength selective optical filter and route said optical signal to the drop port.

An apparatus includes a substrate transmissive of electromagnetic energy of at least a plurality of wavelengths, having a first end, a second end, a first major face, a second major face, at least one edge, a length, a width, and a thickness, at least a first output optic that outputs electromagnetic energy the substrate; and a first input optic oriented and positioned to provide electromagnetic energy into the substrate via at least one of the first or the second major face of the substrate. The first output optic is laterally spaced from the first input optic. A number of reflectors and optional absorbers may be positioned proximate the first major face and/or the second major face to structure electromagnetic energy and/or to translate such from the first input optic to the first output optic. The apparatus may be part of a spectrometer or other optical system.

A wavelength division multiplexing (WDM) device comprises: a substrate; a common port coupled to the substrate and configured for communication of a combined optical signal that includes different signal channels; and filters coupled to the substrate. The common port and the filters define an optical path for the combined optical signal. Each filter is configured to pass one of the signal channels and to reflect any remainder of the signal channels. The filters have a staggered arrangement to facilitate automated assembly. Methods of such automated assembly are also disclosed.

An optical device is provided. The optical device includes a substrate and a plurality of filters. The plurality of filters are disposed over the substrate. Each of the filters includes a support body, a filter layer, and a centrosymmetric spacer. The support body has a first side surface and a second side surface opposite to the first side surface. The filter layer is on the first side surface. The spacer is attached to the first side surface by a second adhesive layer on the first side surface. The centrosymmetric spacer is attached to the filter layer, at least a peripheral portion of the filter layer is free from being covered by the centrosymmetric spacer.

An illumination system for an endoscope has a plurality of light assemblies, including a red assembly with a red light source, a blue assembly with a blue light source, a green assembly with a green light source, and an infrared (IR) assembly with an IR light source. Each light assembly further includes an output beam shape adjuster configured to receive an output beam from the respective light source and adjust the beam angular profile, and an output beam angle adjuster configured to receive a beam from the output beam shape adjuster and adjust the output beam angle. A plurality of dichroic plates are configured to combine output beams of the red assembly, the blue assembly, the green assembly, and the IR assembly.

A wavelength division multiplexing device includes a common port and a plurality of filters that define an optical path. The common port includes a collimator that transmits an optical beam including a plurality of optical signals. Each optical signal is associated with a different wavelength range, and each filter includes an interface having a radius of curvature. One filter is configured to receive the optical beam from the collimator, transmit an optical signal through its interface, and reflect the remaining portion of the optical beam toward another filter. The common collimator and filter are configured so that the reflected portion of the optical beam has a beam waist located in the optical path midway between the filters, and a wavefront radius of curvature at the other filter that matches the filter radius of curvature of that filter. A method of processing light in such a device is also disclosed.