Corning Oca Corporation

Other

Raytheon Company

Derek E Spock

Michael A Scobey

Michael E Grasis

Robert W Lafreniere

Richard C Sharp

Noren Pan

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 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 laser having a gain medium disposed in a resonant cavity having a pair of end reflectors. One of such reflectors has a reflectivity lower than the reflectivity of the other one of the reflectors. The reflectors are arranged to provide a single ended output for the cavity through the one of the reflectors having the lower reflectivity. A saturable absorber is formed on the one of the reflectors having the lower reflectivity. With such an arrangement, fabrication of the saturable absorber on the single ended output coupler is greatly simplified. The gain medium is a doped fiber and the saturable absorber formed on the one of the reflectors having the lower reflectivity is affixed to an end of the doped fiber gain medium. With such an arrangement, a highly efficient, relatively low cost, mode locked laser is provided.

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Watertown, MA, United States of America

Derek E Spock