Abstract: An optical power monitor comprises a fiber and ferrule assembly telescopically embedded in a first glass tube enclosure and a collimating lens telescopically embedded in a second glass tube enclosure. The two glass tube enclosures are bonded together at their respective facing axial ends. The collimating lens is at a first end substantially adjacent the fiber and ferrule assembly. A second end of the lens is coated with a partially transmissive mirror surface for passing a portion of incident light to a photon detector which is bonded to the second glass tube enclosure.

Abstract: An optical filtering element with minimized edge effects, larger clear center aperture, and thermally stable bonding area. The element consists of a modified ball lens. The glass material that comprises the ball lens can be selected from a variety of thermally matched glass specific to the intended application such as BK7, SiO2, et cetera. The lens is polished on two sides so that the polished surfaces are nearly parallel. The polished ball lens(es) are then loaded into a coating fixture and then into a coating chamber. Multiple dielectric layers are applied to one of the polished surfaces, creating a spectral modifying filter. The other side is coated with an anti-reflection coating (some applications do not require the anti-reflection coating). At the completion of the coating run, the now polished and coated ball lenses can be spectrally measured and binned for use.

Abstract: An optical power monitor comprises a fiber and ferrule assembly telescopically embedded in a first glass tube enclosure and a collimating lens telescopically embedded in a second glass tube enclosure. The two glass tube enclosures are bonded together at their respective facing axial ends. The collimating lens is at a first end substantially adjacent the fiber and ferrule assembly. A second end of the lens is coated with a partially transmissive mirror surface for passing a portion of incident light o a photon detector which is bonded to the second glass tube enclosure.

Abstract: A method for making an optical collimating device having three or more ports. A test light having the same wavelength as that at which the filter is designed to operate is transmitted through the input collimator. The angle of incidence is measured, and the location where the reflected beam reaches the ferrule is determined. The data dictates where the output fiber pigtail should be positioned within the ferrule to achieve the measured angle of incidence for that transmitted wavelength and the spacing between input and output pigtails based on the angle of reflection. Multiple ferrules containing two or more pigtails corresponding to a particular filter operating at a particular wavelength are segregated into separate collimator bins that are marked accordingly.

Abstract: An optical filtering element with minimized edge effects, larger clear center aperture, and thermally stable bonding area. The element consists of a modified ball lens. The glass material that comprises the ball lens can be selected from a variety of thermally matched glass specific to the intended application such as BK7, SiO2, et cetera. The lens is polished on two sides so that the polished surfaces are nearly parallel. The polished ball lens(es) are then loaded into a coating fixture and then into a coating chamber. Multiple dielectric layers are applied to one of the polished surfaces, creating a spectral modifying filter. The other side is coated with an anti-reflection coating (some applications do not require the anti-reflection coating). At the completion of the coating run, the now polished and coated ball lenses can be spectrally measured and binned for use.

Abstract: An optical filtering assembly used in temperature compensated multi-port filtering or isolating packages is described. The optical path comprises multiple optical glass fibers inserted into a multi-capillary glass ferrule to produce a fiber-ferrule subassembly, a collimating lens, at least one spectral shaping glass filter and a reflecting element assembly. The collimating lens collimates the light emitted from the input optical fiber into parallel rays, which hit the filter element. Each filter splits the collimated light into two beams. The first (transmitted) beam is spectrally modified as it passes through the filter element, then reflects off the reflecting element traveling back through the same filter element, again spectrally modifying the transmitted beam. Then the beam passes back through the collimating lens in the opposite direction, and couples into the pass band fiber. The second reflective beam is reflected from the filter element through the lens into the reflective optical fiber.

Abstract: An optical filtering assembly used in temperature compensated 3-port filtering or isolating packages is described. The optical path is comprised of two (input and reflective) optical glass fibers inserted into dual-capillary glass ferrule to produce a fiber-ferrule sub-assembly, a collimating (GRIN or aspheric) lens, a spectral shaping glass filter and an output collimating assembly. The lens collimates the light emitted from the input optical fiber into parallel rays, which hit the filter. The filter splits the collimated light into two beams. The transmitted beam is spectrally modified by the filter, and couples into the output collimating assembly. The second beam is reflected from the filter through the lens into the adjacent (reflective) optical fiber. The optical components are assembled and aligned so that the transmitted and reflected light beams are collimated and their insertion losses (IL) are minimized.

Abstract: A method of manufacturing a filter includes the steps of positioning a collimator assembly including a GRIN lens mounted thereto in a movable fixture, placing a UV or thermally curable adhesive on the periphery of the GRIN lens, moving the GRIN lens into engagement with a filter holder having a filter mounted therein, micro-tilting the filter holder while monitoring the input and output signals of the fibers coupled to the GRIN lens for insertion loss less than about 0.1 dB, and applying UV radiation through the filter end of the filter holder to initially cure the aligned subassembly. In a preferred embodiment, the resultant subassembly is subsequently stress relieved and thoroughly cured. In another embodiment, UV radiation is applied to the filter holder GRIN lens interface through one or more apertures formed in the side of the filter holder.

Abstract: A temperature compensated optical filter assembly including a plurality of thin films having temperature dependent indices of refraction which are deposited on a glass substrate so as to form a conventional interference filter thereon. The glass substrate is adhesively coupled to a metal holder such that the deposited thin film interference filter is interposed between the glass substrate and an adhesive layer distributed along a mounting surface of the holder. Thus, a first thermal mismatch stress is applied by the glass substrate onto an inner layer of the interference filter and a second mismatch stress is applied by the holder onto an outer layer of the interference filter, wherein the first and second mismatch stresses depend on the temperature of the filter assembly.

Abstract: A method for tuning a dielectric filter comprises determining filter characteristics of a filter including a cut-on wavelength and a cut-off wavelength taken at a selected gain level. The filter is rotatably attached to a collimator assembly and a light source having a wavelength approximately equal to the cut-on frequency is applied to the filter and rotated to adjust the filter to the cut-on wavelength, and the spectral performance is measured and compared with a cut-on rating value. The method further includes applying a light signal having a wavelength set to a cut-off wavelength, to the filter rotating the filter relative to the collimator assembly, measuring spectral performance, and comparing the measured spectral performance with a cut-off rating value.

Abstract: A method and apparatus of aligning a collimator assembly requiring only a single-axis adjustment and for which the collimator may be paired with any other similarly aligned collimator. A collimator typically includes a fiber grasped by a ferrule. Both the ferrule and a graded-index (GRIN) lens are eventually bonded to the inside of a glass tube with the fiber/lens distance fixed for optimum collimator performance. According to one method of practicing the invention, the tube/lens assembly is fixed, and the ferrule/fiber is slidably inserted into the tube. The position of the ferrule/fiber is adjusted within the tube while the size of the resultant beam is measured at a fixed distance from the output from the lens. If there are two such positions producing the optimum beam size, the position of less separation between the ferrule and fiber is chosen.