Abstract: A connector for one or more optical fibers has a ferrule into which the optical fibers are glued directly with their outer cladding. No stripping of the fibers is required any longer before gluing them to the ferrule and thus, the difficulty of the fragility of the stripped fibers is overcome. The fibers are special fiber having a primary coating with smaller tolerances of ±2 microns. The fibers are arranged on a flexible foil which forms an optical overlay for a printed circuit board.

Abstract: A stabilised gain semiconductor optical amplifier (CG-SOA) includes and active waveguide (1) comprising an amplification medium (2), extending in longitudinal (Z), lateral (X) and vertical (Y) directions, and coupled to a laser oscillation structure comprising at least two resonant cavities (13, 14) extending in first (D1) and second (D2) directions which are different from the longitudinal direction (Z) of the active waveguide (1) and arranged in such a way as to permit the establishment of laser oscillations having at least two different relaxation oscillation frequencies.

Abstract: An optical switch with a compact form factor includes a multiple-fiber collimator and an angle tuning element for deflecting an optical beam from an input fiber into one of at least two output fibers. The angle tuning element may be provided between a pair of coaxially-aligned collimators, one of which is the multiple-fiber collimator. Alternatively, the angle tuning element may be provided between the multiple-fiber collimator and a reflective surface, so that only one collimator is required and the optical switch may be designed to have its input and output ports on the same side.

Abstract: A transmitter on an integrated circuit chip is disclosed that employs a laser, modulator, and a dispersion compensator module and a modulator for overcoming chromatic dispersion and polarization dependent loss effects. With the present invention, the dispersion compensator module is placed on a chip, either integrated or monolithic, for operation with a laser and a modulator without the need to compensate for dispersion within a separate unit that is not part of the chip. The dispersion compensator module can be implemented, for example, with a ring resonator, an etalon or a Mach-Zehnder interferometer. In a first aspect of the invention, the optical transmitter module of the present invention provides a cost-effective solution for upgrading from an existing optical network to a faster optical network, such as upgrading from a 2.5 Gbps to a 10 Gbps network.

Abstract: The present invention generally relates to dynamic thermal management of a device. In one aspect, a method for thermally controlling a device is provided. The method includes setting a value of a set point in a thermoelectric cooler, wherein the set point corresponds to a first operating state. The method also includes monitoring a condition of the device to determine if the device is in the first operating state or a second operating state. Additionally, the method includes dynamically altering the value of the set point according to an algorithm upon determination that the device is in the second operating state. In another aspect, a method for dynamically controlling a device having a thermoelectric cooler is provided. In yet a further aspect, a system for dynamic thermal management of a device is provided.

Abstract: One embodiment of the present invention includes a plurality of first optical elements and a second optical element optically coupled to one another in cascaded fashion. Each first optical element has a group delay response characterized by a first period such that only one group delay peak occurs within a first channel. By contrast, the second optical element has a group delay response characterized by a second period, which is less than the first period, such that more than one group delay peak occurs within the first channel. The preferred embodiment uses cascaded GT etalons to provide the desired group delay responses. One advantage of the present invention is that the passband of the dispersion compensator is increased relative to prior art designs without increasing insertion losses. Alternatively, the same passband common in prior art designs may be achieved with fewer GT etalons, thereby reducing insertion losses.

Abstract: An improved optical switch utilizes one polarization modulator, with the beam components traversing it twice. Because of the twice traverse, the extinction ratio of the switch is doubled without the addition of another polarization modulator, thus avoiding the costs of additional optical components. With no additional components, the switch is more compact than conventional switches with the same extinction ratio. Fewer components also result in more thermal and long-term stability and less crosstalk.

Abstract: The present invention generally relates to an air cavity plastic package for a high frequency optical device. In one aspect, a module package for a high frequency optoelectronic device is provided. The module package includes an upper plastic housing having an upper cavity formed therein and a lower plastic housing having a lower cavity formed therein. The upper housing and the lower housing are configured to mate together such that the cavities form an enclosed air cavity between the housings. Additionally, upon creating a seal between the housings, an optical feed through is realized. The module package further includes a plurality of conductors disposed in the lower housing, each conductor having an upper end and a lower end, wherein the upper end is connectable to a chip disposed in the air cavity and the lower end is connectable to a board. In another aspect, a method of packaging and assembling a high frequency optical device is provided.

Abstract: An optical modulator comprises a Z-cut lithium niobate substrate (21) on which is formed a Mach-Zehnder interferometer having two generally parallel waveguides (23, 25) lying beneath a buffer layer of dielectric material (27). First and second ground electrodes (29, 33) and a hot electrode (31) are disposed on the buffer layer (27), the first and second ground electrodes (29, 33) being spaced either side of the hot electrode (31), the hot electrode (31) and the first ground electrode (29) being proximate to at least apart of the respective waveguides (25, 23). The electrode structure is unsymmetrical in that (a) the hot electrode and the first ground electrode each have a width substantially less than that of the second ground electrode and or (b) the spacing between the first ground and hot electrodes is different from the spacing between the second ground and hot electrodes. whereby a range of chirp values can be obtained.

Abstract: A group delay compensation equalizer is disclosed that employs a single channel four-port WDM device for compensating the group delay experienced by a plurality of wavelengths transmitted over different paths. The transmission differential between two wavelengths is compensated by transmitting the two wavelengths through two different paths where the fiber length in reflecting the second wavelength is equal to the transmission time difference between the two wavelengths. The single channel four-port group delay equalizer effectively provides a unidirectional signal flow, as compared to the conventional equalizer that transmits optical signals bi-directionally. The present invention reduces the cost of a group delay equalizer by simplifying the use of multiple three-port WDM devices into a single channel four-port WDM device.

Abstract: A reconfigurable thin film based dense wavelength division multiplexing (DWDM) device is described for hitless switching of wavelengths by employing a reconfigurable filtering device. The reconfigurable filtering device is based on a mechanical switching of a filtering chip which has a thin film coated a first one-half of a first face for interference wavelength filtering and has a gold-mirror coated on a second one-half of the first face for high reflection.

Abstract: In a first aspect, the present invention comprises an optical filter comprising a fiber having a core and a cladding and a light-absorbing coating applied onto a portion of the fiber cladding, the coating attenuating loosely bound cladding modes. In another aspect, the invention comprises a fiber amplifier apparatus comprising fibers for delivering pump laser light and for monitoring signal light and at least one photodetector optically coupled to a monitoring fiber, wherein either an optical filter is disposed between a monitoring fiber and a photodetector or at least one of the fibers has a core and a cladding and a light-absorbing coating applied onto a portion of the fiber cladding. A method in accordance with the present invention includes providing an optical amplifier having fibers for delivering pump laser light and for monitoring signal light, and applying a light-absorbing coating onto a portion of one of said fibers.

Abstract: An optical receiver is disclosed comprising an erbium-doped fiber amplifier (EDFA) that is coupled to a photodiode and transimpedance amplifier without filtering output light signal in the EDFA. Optionally, a clock/data regenerator can be coupled to the electrical output of the transimpedance amplifier for compensating for noise distortion and timing jitter for affecting the control loop feeding back for adjusting the electrical current into a pump laser of an optical pre-amplifier. Furthermore, the optical receiver of the present invention can also be implemented in a transponder.

Abstract: An optical filter comprises a waveguide and a plurality of Slanted Bragg Gratings written in the waveguide, wherein at least two of the Slanted Bragg Gratings overlap one another. A method of producing an optical filter comprises the steps of passing an ultraviolet light through a first portion of a chirped phase mask onto a first portion of a photosensitive waveguide so as to form a first Slanted Bragg Grating in the first portion of the waveguide and passing the ultraviolet light through a second portion of the chirped phase mask onto a second portion of the photosensitive waveguide so as to form a second Slanted Bragg Grating in the second portion of the waveguide, wherein the first and second Slanted Bragg Gratings overlap one another. A further annealing step may cause a spectrum of the filter to match a target spectrum.

Abstract: The present invention describes a structure and method for a multi-ports WDM device for compensating the filter distortion while reducing insertion loss. The multi-ports WDM device comprises a 4-fiber collimator having a grin lens and a 2-fiber collimator having a lens where the focal plane of the second lens is shorter than the focal plane of the first grin lens Ands with aspheric surface. When a light signal travels through the first lens in the 4-fiber collimator to a filter, the film on the filter causes distortion to the light signal resulting in a large insertion loss. To compensate for the insertion loss, the lens on the 2-fiber collimator has a aspheric function and a shorter focal plane than the grin lens on the 4-fiber collimator. The type of grin lens used in the 4-fiber collimator is different than the lens used in the 2-fiber collimator. Effectively, the lens in the 2-fiber collimator operates to de-focus a light signal relative to the grin lens in the 4-fiber collimator.

Abstract: A reconfigurable optical add-drop multiplexer is disclosed that enables Optical Multiplex Section (OMS) shared protection rings. The ROADM comprises a first optical supervisory module, coupled to a first amplifier module, which in turn is coupled to a first broadcast and select module, where the first broadcast and select module is coupled to both a first multiplexer/demultiplexer module and the first optical supervisory module. Each optical supervisory module has an optical tap for tapping a fraction of an outgoing OMS signal that is fed back or looped back to a 2×1 optical switch in the optical supervisory module.

Abstract: A method for producing a Bragg grating in an optical waveguide device such as an optical fiber. The optical fiber is exposed to a UV source through a phase mask and this produces a Bragg grating on the fiber. The grating on the fiber is overexposed such that the gratings are stronger than desired. The fiber is then annealed to stabilize the gratings left behind. The gratings left behind are still stronger than desired. The fiber is then exposed to a point source laser that reduces the index change for selected portions. This trims the existing grating to result in the desired grating strength.

Abstract: Chromatic dispersion of thin-film based mux/demux and add/drop modules can be reduced. Thin-film devices can be arranged in a specific order in the module. Multiple kinds of filters are used to remove “even” and “odd” channels, or other divisions of channels. At least one filter type can be designed for a higher dispersion in transmission but lower dispersion in reflection. At least another filter type can be designed in conjunction with the first filter type such that the sum of the dispersion from the reflection and that from transmission is as low as possible. This ensures that the overall dispersion of the odd and even channels is lower than what one can achieve with one uniform filter.

Abstract: A re-configurable channel dropping de-multiplexer comprises an input, an output, a first 1×2 optical switch optically coupled to the input, a second 1×2 optical switch optically coupled to the output, a plurality of 2×2 optical switches optically coupled between the first and second 1×2 optical switches, a plurality of inter-switch optical couplings optically coupled between each pair of adjacent optical switches, a plurality of channel band pass filter assemblies, each optically coupled between two optical switches and a plurality of channel drop ports, each channel drop port being optically coupled to a respective channel band pass filter assembly.

Abstract: A liquid crystal optical performance monitor is described that employs a liquid crystal tunable filter for receiving a P-polarization beam and a rotated S-polarization beam from a C-polarizer. The rotated S-polarization beam from a birefringent crystal in C-polarizer propagates through a waveplate which rotates the polarization by 90 degrees, resulting in the rotated S-polarization beam having the same polarization orientation as the P-polarization beam. The liquid crystal tunable filter therefore receives just the P-polarization orientation. The C-polarizer and a small beam collimator are rotated so that the polarization orientation of the P-polarization beam and the rotated S-polarization beam matches the orientation of the LC inside the LC cavity of the LC tunable filter. In a first embodiment, the liquid crystal optical performance monitor is implemented with a photodiode. In a second embodiment, the liquid crystal optical performance monitor is implemented with a bi-cell photo diode.