Abstract: An optical wavelength-division multiplexing (“WDM”) device utilizing a mechanism of folded optical-path includes multiple collimators, optical filters, prism, and glass plate. The collimators are capable of collimating optical lights for facilitating free-space optical communication. The optical filters optically coupled with the collimators provide filtering functions to separate optical wavelengths in accordance with the configurations or characteristics of optical filters. The prism having an interface surface and two side surfaces is configured to direct or redirect optical beams based on the angle of incidence (“AOI”) of each optical beam received. The glass plate, in one embodiment, physically configured to be situated in parallel with the collimators is capable of providing free-space optical paths for facilitating separation of wavelengths.

Abstract: Method and multiport free-space wavelength division multiplexing (“WDM”) device capable of handling multiple optical signals carried in multiple wavelengths (“?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 ?n and subsequently extract a first wavelength (“?1”) from ?n. A second optical beam is formed by the remaining of ?n. The collimator, in one example, receives ?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.

Abstract: A multiport free-space wavelength division multiplexing (“WDM”) device is capable of handling multiple optical signals carried in multiple wavelengths (“?n”) using a prism. The WDM device includes an input collimator, prism, and optical filter. The input collimator receives an optical beam containing multiple wavelengths ?n traveling through free-space. The prism uses at least two (2) surfaces to generate a first optical beam which travels in opposite direction of the optical beam. The optical filter is situated at a predefined angle with respect to the interface surface of the prism for facilitating frequency separation as well as extracts a first wavelength (“?1”) from ?n to form a first light signal with ?1 and form a second optical beam with the remaining wavelengths of ?n. A collimator is used to guide the first light signal to a port.

Abstract: Method and multiport free-space wavelength division multiplexing (“WDM”) device capable of handling multiple optical signals carried in multiple wavelengths (“?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 ?n and subsequently extract a first wavelength (“?1”) from ?n. A second optical beam is formed by the remaining of ?n. The collimator, in one example, receives ?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.

Abstract: An optical wavelength-division multiplexing (“WDM”) device utilizing a mechanism of folded optical-path includes multiple collimators, optical filters, prism, and glass plate. The collimators are capable of collimating optical lights for facilitating free-space optical communication. The optical filters optically coupled with the collimators provide filtering functions to separate optical wavelengths in accordance with the configurations or characteristics of optical filters. The prism having an interface surface and two side surfaces is configured to direct or redirect optical beams based on the angle of incidence (“AOI”) of each optical beam received. The glass plate, in one embodiment, physically configured to be situated in parallel with the collimators is capable of providing free-space optical paths for facilitating separation of wavelengths.

Abstract: A multiport free-space wavelength division multiplexing (“WDM”) device is capable of handling multiple optical signals carried in multiple wavelengths (“?n”) using a prism. The WDM device includes an input collimator, prism, and optical filter. The input collimator receives an optical beam containing multiple wavelengths ?n traveling through free-space. The prism uses at least two (2) surfaces to generate a first optical beam which travels in opposite direction of the optical beam. The optical filter is situated at a predefined angle with respect to the interface surface of the prism for facilitating frequency separation as well as extracts a first wavelength (“?1”) from ?n to form a first light signal with ?1 and form a second optical beam with the remaining wavelengths of ?n. A collimator is used to guide the first light signal to a port.

Abstract: The present invention is a lens system used to relay the light from one region to another and increase the workable optical path length to make Wavelength Division Multiplexing (WDM) devices with a high port count. Inside the WDM device based on thin filters, collimators produce parallel light beams, and when the light path is over the collimator working distance, there can be substantial coupling loss. However, within the working distance, light can pass through the filters and collimators to follow the zig-zag pattern and eventually couple into a desired fiber without substantial insertion loss. A lens relay system can increase the optical path length to achieve high port count DWDM without fiber routing that takes more space and without a high coupling loss that is caused by multiple coupling between free space and fibers.

Abstract: In the field of fiber optic communication, Wavelength Division Multiplexing (WDM) devices are used to combine wavelengths of light onto a single strand of fiber. To construct a WDM device, the optical components such as mirrors and filters must be cut in precise angles and positioned in parallel orientations to separate or combine wavelengths of light. The expenditure for implementation of free-space WDM devices can be prodigiously high and costly for compact devices. Techniques for designing optical components to manufacture a compact free-space WDM device including a surface mount assembly are disclosed. In addition to the common optical components used in a WDM device, a hybrid subassembly is included to assist in the orientation of optical components when manufacturing the compact device.

Abstract: The invention teaches the design and assembly configurations for a free space DWDM device. Particularly, when using the free space DWDM devices for channel spacing less than 200 GHz, a small angle of incidence requires a longer optical path and adjustments must be made by folding the optical path or using double layers of optical components such as collimators to shorten the device and obtain the compact dimensions of the DWDM device.

Abstract: Described are tunable multiport optical filters that filter systems with many optical channels in a convenient and cost-effective manner. The tunable multiport optical filters of the invention are simple in design and have few optical components. The basic elements are a dispersion element and a rotating reflector. With properly arranged arrays of input and output optical fibers, individual wavelength components from a selected input beam are spatially separated and steered by the rotating reflector to selected output locations. The optical properties from the selected components may be measured by one or more photodetectors. The filters are also useful for selecting and routing optical signals.

Abstract: Described are tunable multiport optical filters that filter systems with many optical channels in a convenient and cost-effective manner. The tunable multiport optical filters of the invention are simple in design and have few optical components. The basic elements are a dispersion element and a rotating mirror. With properly arranged arrays of input and output optical fibers, individual wavelength components from a selected input beam are spatially separated and steered by the rotating mirror to selected output locations. The optical properties from the selected components may be measured by one or more photodetectors. The filters are also useful for selecting and routing optical signals.

Abstract: An LC-based optical device compensates for differences in optical path lengths of polarization components of input beam. As a result, PDL and PMD of the optical device are reduced. The compensation mechanism may be a glass plate that is disposed in an optical path of a polarization component so that the optical path length of that polarization component can be made substantially equal to the optical path length of the other polarization component that traverses through a half-wave plate. Another compensation mechanism is a birefringent displacer that has two sections sandwiching a half-wave plate, wherein the two sections are of different widths and the planar front surface of the birefringent displacer can be positioned to be non-orthogonal with respect to the incident input light beam.

Abstract: An LC-based optical device compensates for differences in optical path lengths of polarization components of input beam. As a result, PDL and PMD of the optical device are reduced. The compensation mechanism may be a glass plate that is disposed in an optical path of a polarization component so that the optical path length of that polarization component can be made substantially equal to the optical path length of the other polarization component that traverses through a half-wave plate. Another compensation mechanism is a birefringent displacer that has two sections sandwiching a half-wave plate, wherein the two sections are of different widths and the planar front surface of the birefringent displacer can be positioned to be non-orthogonal with respect to the incident input light beam.

Abstract: An LC-based optical device compensates for differences in optical path lengths of polarization components of input beam. As a result, PDL and PMD of the optical device are reduced. The compensation mechanism may be a glass plate that is disposed in an optical path of a polarization component so that the optical path length of that polarization component can be made substantially equal to the optical path length of the other polarization component that traverses through a half-wave plate. Another compensation mechanism is a birefringent displacer that has two sections sandwiching a half-wave plate, wherein the two sections are of different widths and the planar front surface of the birefringent displacer can be positioned to be non-orthogonal with respect to the incident input light beam.

Abstract: Described are tunable multiport optical filters that filter systems with many optical channels in a convenient and cost-effective manner. The tunable multiport optical filters of the invention are simple in design and have few optical components. The basic elements are a dispersion element and a rotating reflector. With properly arranged arrays of input and output optical fibers, individual wavelength components from a selected input beam are spatially separated and steered by the rotating reflector to selected output locations. The optical properties from the selected components may be measured by one or more photodetectors. The filters are also useful for selecting and routing optical signals.

Abstract: An optical device has the structure to perform switching and attenuation of an optical beam with reduced polarization dependent loss (PDL). The optical device includes a birefringent displacer and two liquid crystal (LC) structures. The first LC structure is used to condition s-polarized components of the optical beam and the second LC structure is used to condition p-polarized components of the optical beam. Each LC structure has a separate control electrode so that the s-polarized components of the optical beam and the p-polarized components of the optical beam can be conditioned differently and in such a manner that reduces PDL. The optical device may be configured for processing multiple input light beams, such as the multiple wavelength channels de-multiplexed from a wavelength division multiplexed (WDM) optical signal.

Abstract: An LC-based optical device compensates for differences in optical path lengths of polarization components of input beam. As a result, PDL and PMD of the optical device are reduced. The compensation mechanism may be a glass plate that is disposed in an optical path of a polarization component so that the optical path length of that polarization component can be made substantially equal to the optical path length of the other polarization component that traverses through a half-wave plate. Another compensation mechanism is a birefringent displacer that has two sections sandwiching a half-wave plate, wherein the two sections are of different widths and the planar front surface of the birefringent displacer can be positioned to be non-orthogonal with respect to the incident input light beam.

Abstract: An optical device has the structure to perform switching and attenuation of an optical beam with reduced polarization dependent loss (PDL). The optical device includes a birefringent displacer and two liquid crystal (LC) structures. The first LC structure is used to condition s-polarized components of the optical beam and the second LC structure is used to condition p-polarized components of the optical beam. Each LC structure has a separate control electrode so that the s-polarized components of the optical beam and the p-polarized components of the optical beam can be conditioned differently and in such a manner that reduces PDL. The optical device may be configured for processing multiple input light beams, such as the multiple wavelength channels de-multiplexed from a wavelength division multiplexed (WDM) optical signal.

Abstract: An optical device performs both switching and attenuation of an optical beam, where the beam has an arbitrary combination of s-polarized and p-polarized components. The optical device includes a birefringent displacer, a liquid crystal (LC) beam-polarizing structure having six subpixels organized in a first polarization group and a second polarization group, a half-wave plate positioned for polarization control of the second polarization group, and a polarization separating and rotating assembly. The structure of the LC beam-polarizing structure allows for 1×2 switching and attenuation control with a single control signal. The optical device may be configured for processing multiple input light beams, such as the multiple wavelength channels de-multiplexed from a wavelength division multiplexed (WDM) optical signal.

Abstract: A dynamic gain equalizer (DGE) includes: a mirror; an electrode; and a lever with a first end and a second end opposite to the first end, where the lever is capable of rotating about a fulcrum, where the lever rotates the first end toward the electrode when the electrode is charged such that the second end blocks a portion of a channel from reaching the mirror, where an unblocked portion of the channel is reflected by the mirror. By manipulating the charge on the electrode, the rotation of the lever is controlled, determining how much of the light is blocked by the lever. Each lever in an array can attenuate a channel or a group of channels of a composite optical signal by a different amount. The DGE provides a significant range of blockage and can be closely spaced. It provides ease in integrating channel monitoring into the DGE.