Corning Oca Corporation

Optical Corporation of America

Other

Michael A Scobey

Derek E Spock

Michael E Grasis

Robert W Lafreniere

Xinxiong Zhang

Stanley L Bryn

An optical multiplexing device is disclosed for multiplexing optical signals, for example, for a fiber-optic telecommunication system employing wavelength division multiplexing. The optical multiplexing device has a filter assembly defining a light path, preferably a multi-bounce zigzag expanded beam light path, from a common port at least to a first channel port and then a second channel port and then a pass-through port. The first channel port has a first optical filter element, for example, a multi-cavity interference filter, which is transparent to a wavelength sub-range within the wavelength range passed by the common port and the pass-through port, and substantially reflective of other wavelengths within such wavelength range. The second channel port includes a second optical filter element having light transmittance and reflectance properties substantially the same as those of the first optical filter element. The optical multiplexing device can be used to extract or drop a selected wavelength sub-range, most typically a single channel signal, from the multiplexed light, and to then inject a new signal into the multiplexed light at that same wavelength sub-range. In accordance with preferred embodiments, the optical multiplexing device serves as an add/drop filter arrangement to extract the signal of a particular channel and then immediately use the available channel by injecting a new signal at that same wavelength sub-range.

Add/drop optical multiplexing device

An optical multiplexing device is provided comprising multiple wavelength division multiplexers cascaded together. A first one of the wavelength division multiplexers has a common port and multiple optical ports which are optically coupled to the common port. The common port may be optically coupled to a trunk line of a system employing wavelength division multiplexing, for example, a fiber-optic telecommunication system employing 4, 8, 16 or other number of multiplexed channels. The optical ports include multiple channel ports, each of which is transparent to a corresponding wavelength sub-range and reflective of other wavelengths. The second wavelength division multiplexer has a common port optically coupled to one of the optical ports of the first wavelength division multiplexer. The second wavelength division multiplexer also has multiple optical ports which are optically coupled to its common port and include multiple wavelength-selective channel ports. A waveguide, such as a fiber-optic line, can optically connect the common port of the second wavelength division multiplexer to an optical port of the first wavelength division multiplexer. The cascaded WDMs each may be optically coupled to the output of a passive coupler and a housing may be provided defining an enclosed space in which the optical multiplexing device is mounted. Optionally, additional WDMs may be cascaded with the first two WDMs in a parallel or branched formation, an in-line formation or some combination. Preferably, the channels are interleaved, such that they are removed from the multiplexed signal in certain non-sequential order. The optical multiplexing device also may employ compound interleaving wherein adjacent channels are multiplexed by different ones of the cascaded WDMs. The optical multiplexing devices can operate to add signals, remove signals or a combination of both.

Cascading optical multiplexing device

An external cavity, single mode laser has a semiconductor gain medium, such as a diode laser, and a monolithic prism assembly positioned in an external resonant cavity having a length of 10 mm or less. The monolithic prism assembly includes a transparent substrate carrying a thin film Fabry-Perot interference filter on a face which is tilted to the path of travel of the laser light in the external cavity. Translation of the monolithic prism assembly including transversely to the optical axis provides continuous mode-hop-free tuning of the laser output wavelength. The Such optical devices can be economically mass produced in advantageously small size, having reproducible spectral performance properties held within tight tolerances. Significantly advantageous applications include dense wavelength division multiplexing systems requiring tightly spaced wavelength subranges for each of multiple channels. High wavelength stability against temperature and humidity changes, etc., can be achieved.

External cavity semiconductor laser with monolithic prism assembly

An optical multiplexing device demultiplexes collimated light from a fiber-optic source into separate individual wavelength sub-ranges or channels, and/or multiplexes separate channels to a common fiber-optic waveguide or other destination. An optical block defines an optical gap between two parallel surfaces having an optical port on a first such parallel surface for passing the multi-channel collimated light into the optical gap. A channel port and at least one other reflective element, e.g., multiple channel ports arrayed in spaced relation to each other, are secured to the optical block at the parallel surfaces, providing an unobstructed, epoxy-free multi-point light path within the optical gap. At each channel port an interference filter secured to the optical block spans the optical gap. Each filter transmits a wavelength sub-range of the multi-channel collimated light passed by the optical port, and reflects other wavelengths. Thus, a wavelength sub-range of the multi-channel light passed through the optical gap to a first channel port, which is in-band of that first channel port, is transmitted through that first channel port. Light not transmitted through that first channel port is reflected back through the optical gap, e.g., to strike a second channel port, at which a second, different wavelength sub-range is transmitted. The reflected optical signal thus cascades in a 'multiple-bounce' sequence through the optical gap of the multiplexing device, sequentially adding and/or removing channels.

Multiplexing device with precision optical block

A method and apparatus for producing optical films on substrates having extremely high packing densities of the same quality as those films produced by ion beam sputtering including a vacuum chamber with a conventional magnetron sputtering system and unusually high speed vacuum pump means. The low pressure of inert gas created by said high speed vacuum pump means being in the range of 5.times.10.sup.-5 Torr to 1.5.times.10.sup.-4 Torr and the magnetron sputtering system being at least 16' from said substrates. A gas manifold around the magnetron and target material confines the inert working gas in the vicinity of the magnetron and as the gas diffuses and expands into the chamber the high speed vacuum pump means removes the expanded gas from the chamber at a high speed. An ion gun directs ionized reactant gas toward the substrates which has the effect of improving film stoichometry as well as reducing reactant gas at the magnetron. Multiple magnetron assemblies, multiple target materials and compound target materials may be used.

Low pressure reactive magnetron sputtering apparatus and method

An optical multiplexing device spatially disburses collimated light from a fiber optic waveguide into individual wavelength bands, or multiplexes such individual wavelength bands to a common fiber optic waveguide or other destination. The optical multiplexing device has application for dense channel wavelength division multiplexing (WDM) systems for fiber optic telecommunications, as well as compact optical instrument design. Multiple wavelength light traveling in a fiber optic waveguide is separated into multiple narrow spectral bands directed to individual fiber optic carriers or detectors. An optical block has an optical port for passing the aforesaid multiple wavelength collimated light, and multiple ports arrayed in spaced relation to each other along a multiport surface of the optical block. A continuous, variable thickness, multi-cavity interference filter extends on the multiport surface of the optical block over the aforesaid multiple ports. At each of the multiple ports the continuous interference filter transmits a different wavelength sub-range of the multiple wavelength collimated light passed by the optical port, and reflects other wavelengths. Multicolor light passed to the optical block from the optical port is directed to a first one of the multiple ports on an opposite surface of the optical block. The wavelength sub-range which is 'in-band' of such first one of the multiple ports is transmitted through that port by the local portion of the continuous, variable thickness interference filter there, and all other wavelengths are reflected. The light not transmitted through the first port is reflected to strike a second port, at which a second (different) wavelength band is transmitted and all other light again reflected. The reflected optical signals thus cascades in a 'multiple-bounce' sequence down the optical block of the multiplexing device, sequentially removing each channel of the multiplexed signal. In reverse operation, individual channels are combined in the optical block and transmitted through the optical port.

Optical multiplexing device

A method and apparatus for sputtering coatings on substrates in very high vacuum conditions is shown where the high vacuum is made possible by a supply of inert gas localized at the sputtering source and confined by velocity and by physical constraints in the area of the source and is depleted as the inert gas flows into a larger vacuum chamber. Additional methods to improve testing of substrates being coated and to enhance the sputtering process by use of ion gun directed reactant toward the substrates are disclosed. The method and apparatus are especially effective in allowing large spacing between source and substrates in the sputtering process. The large spacing provides good coating uniformity on large substrates.

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Marlborough, MA, United States of America

Michael A Scobey