Abstract: An optical communications system has a selective block/add capability of an optical channel. An optical beam separator receives and separates an input mixed optical beam into a separated optical channel and a remainder optical beam. A block/add unit receives as an input the separated optical channel and produces as an output a controllably modified separated optical channel. The block/add unit includes a source of an add input optical signal, and a controllable mirror. The controllable mirror is controllable between a first state in which the controllable mirror does not block the path of the separated optical channel, so that the separated optical channel is the output of the block/add unit, and a second state in which the controllable mirror blocks the path of the separated optical channel, and also reflects the add input optical signal as the output of the block/add unit.

Abstract: A first part has first, second and third inwardly-facing surface portions angularly spaced about an axis, and a second part has outwardly-facing fourth, fifth and sixth surface portions spaced angularly about the axis, a radial distance from the axis to each surface portion decreasing progressively in a given direction along the axis. Each of the fourth, fifth and sixth surface portions faces, is closely adjacent to, and is substantially congruent in shape with a respective one of the first, second and third surface portions. At least one of the first and second parts is an optical component.

Abstract: An optical communications system has a selective block/add capability of an optical channel. An optical beam separator receives and separates an input mixed optical beam into a separated optical channel and a remainder optical beam. A block/add unit receives as an input the separated optical channel and produces as an output a controllably modified separated optical channel. The block/add unit includes a source of an add input optical signal, and a controllable mirror. The controllable mirror is controllable between a first state in which the controllable mirror does not block the path of the separated optical channel, so that the separated optical channel is the output of the block/add unit, and a second state in which the controllable mirror blocks the path of the separated optical channel, and also reflects the add input optical signal as the output of the block/add unit.

Abstract: A first part has first, second and third inwardly-facing surface portions angularly spaced about an axis, and a second part has outwardly-facing fourth, fifth and sixth surface portions spaced angularly about the axis, a radial distance from the axis to each surface portion decreasing progressively in a given direction along the axis. Each of the fourth, fifth and sixth surface portions faces, is closely adjacent to, and is substantially congruent in shape with a respective one of the first, second and third surface portions. At least one of the first and second parts is an optical component.

Abstract: A sight includes at least one lens having a lens central axis parallel to a lens through-thickness direction and which is laterally physically truncated parallel to the lens central axis, and a sight housing in which the at least one lens is received. The sight housing has a horizontal dimension, and a vertical dimension less than the horizontal dimension. A greatest dimension of the lens is parallel to the horizontal dimension of the sight housing.

Abstract: An optical communications system has a selective block/add capability of an optical channel. An optical beam separator receives and separates an input mixed optical beam into a separated optical channel and a remainder optical beam. A block/add unit receives as an input the separated optical channel and produces as an output a controllably modified separated optical channel. The block/add unit includes a source of an add input optical signal, and a controllable mirror. The controllable mirror is controllable between a first state in which the controllable mirror does not block the path of the separated optical channel, so that the separated optical channel is the output of the block/add unit, and a second state in which the controllable mirror blocks the path of the separated optical channel, and also reflects the add input optical signal as the output of the block/add unit.

Abstract: A sighting device includes a fixed-position objective lens group lying on an optical axis, an eyepiece lens group lying on the optical axis, and a variable-position objective lens group lying on the optical axis and positioned between the fixed-position objective lens group and the eyepiece lens group. A variable-lens position of the variable-position objective lens group relative to the fixed-position objective lens group or the eyepiece lens group may be controllably varied. A mechanical aperture stop lies on the optical axis between the fixed-position objective lens group and the eyepiece lens group. A stop axial position and/or a stop size of the mechanical aperture stop may be varied according to the position of the variable-position objective lens group.

Abstract: The thin-film optical filters and transmitted-light collimators of a multistage optical multiplexer/demultiplexer apparatus are assembled by locating the thin-film optical filters so that an incident light beam is incident upon and reflected sequentially from each thin-film optical filter to the next thin-film optical filter, and orienting each thin-film optical filter to produce a respective angle-of-incidence of the incident light beam on the thin-film optical filter so that a desired transmitted light beam is transmitted therethrough with a maximum intensity. The transmitted-light collimators are positioned to receive the respective transmitted light beams with minimal insertion loss. The respective steps of positioning are performed independently of, but after, the respective steps of orienting for each multiplexer/demultiplexer stage.

Abstract: Add/drop functions of light signals in an optical fiber light transmission system are performed using a group of bandpass light filters, wherein each of the group of bandpass light filters is operable to reflect a reflected wavelength band and transmit a transmitted wavelength band. A filter module is positioned to selectively place any of the group of bandpass light filters into a light path of the optical fiber light transmission system. A first add/drop function is accomplished by first positioning a first selected one of the bandpass light filters into the light path using a drive mechanism, directing the input light beam onto the first selected one of the bandpass light filters, performing the first add/drop function on the input light beam relative to a first band light signal in a first wavelength band, and removing the first selected one of the bandpass light filters from the light path using the drive mechanism.

Abstract: A lens assembly is prepared by placing a first lens into an interior of a lens housing with a first side of the lens contacting a seat in a side wall of the lens housing. An annular first retainer is placed into the lens housing contacting a second side of the first lens. A second lens is placed into the lens housing with a first side of the second lens contacting the annular first retainer. An annular second retainer is placed into the lens housing contacting the second side of the second lens. The annular first retainer and the annular second retainer are affixed to the side wall with respective metallic solder or weld joints. The first lens and the second lens are not affixed to the inner side wall.