Dicing and testing optical devices, including thin film filters
Granted: February 20, 2003
Application Number:
20030036212
A technique for fabricating a plurality of thin film filters (“TFFs”), and other optical devices, from a wafer. A device or TFF wafer is affixed to a carrier having a pattern of notches formed thereon corresponding to a pattern into which the wafer is to be diced to form the TFFs. The notches are sized to allow clearance of a dicing apparatus. The wafer is diced at least partially into the notches to form the TFFs, and the TFFs may be individually optically tested with a…
Birefringence compensated integrated optical switching or modulation device
Granted: February 6, 2003
Application Number:
20030026518
A planar waveguide Mach-Zehnder interferometer (MZ) has improved performance as a variable optical attenuator as well as a thermo-optic switch (TOS) with reduced polarization dependent loss (PDL) in high attenuation states. The PDL was reduced by correcting for the increased birefringence that occurs on heating one waveguide arm by making the two waveguides inherently asymmetric, such that when one of the waveguides is heated, the differential birefringence of the two arms becomes zero.…
Multi-wavelength switchable laser
Granted: January 16, 2003
Application Number:
20030012232
A multi-wavelength switchable laser system configured at known wavelengths without the need for wavelength feedback/locking control. The system includes an optical gain element, e.g. a pump source; a laser cavity defined by electrically activated Bragg gratings, each having a prescribed operational wavelength; a control module for controlling actuation of the gratings to activate a selected one of the gratings for operation at a selected operational wavelength; and an appropriate lens…
Beam splitting device
Granted: January 2, 2003
Application Number:
20030002155
An improved design of beam splitting device is described that is formed by cutting a birefringent material to predetermined dimensions. The beam splitting device resolves input light into mutually orthogonal linearly polarised beams. The mutually orthogonal linearly polarised beams propagate on either side of an axis as defined by the propagation axis of the input light. Such beam splitting devices lends themselves to a reduction in the overall dimensions of an optical system. In…
Integrated optical amplifier
Granted: January 2, 2003
Application Number:
20030002771
A waveguide device for optical amplification and light amplification by stimulated emission radiation comprises an optical medium formed from a bulk glass. The optical medium is fused to a planar substrate to form a lower cladding. The bulk glass is subsequently thinned, patterned and coated with an upper cladding to form waveguide channels with sufficient mode confinement and mode field dimension compatible with direct coupling to optical fibers to achieve low insertion loss and a…
Diffraction-compensated integrated WDM
Granted: January 2, 2003
Application Number:
20030002787
A diffraction-compensated WDM (wavelength division multiplexer) uses TTFs (thin film filters) as concave mirrors. The WDM has a plurality of filter elements for guiding the optical signal along a predetermined optical path, each filter element being transparent to a predetermined wavelength range and including compensating means for at least partially compensating for diffraction of the optical signal. Each filter element has a thin film coated on a substrate, and the compensating means…
Mixing method and apparatus for characterizing optical modulator
Granted: December 26, 2002
Application Number:
20020196444
A mixed frequency-based method and arrangement for characterizing an electro-optic modulator is configured to vary the tuning of a laser beam, to be modulated by the optical modulator, simultaneously with and in the same manner as the variation in frequency of the modulation signal. The effect of this dual modulation approach is a modulated laser beam, in which the frequency difference between the carrier component of the laser beam and sideband energy produced by the modulation signal…
Waveguide structure
Granted: December 26, 2002
Application Number:
20020197041
A glass planar waveguide structure, typically on a glass wafer or chip, has a core region, a contiguous narrow cladding region encompassing the core region, and an outer region practically extending over the rest of the wafer. The core region and the outer region are implanted with outside ions by ion diffusion, whereby the refractive index of the core and of the outer region are similar. The outer region forms an artificial waveguide to enhance the uniformity of physical properties of…
Transceiver device for transmitting and receiving optical signals
Granted: December 19, 2002
Application Number:
20020191917
The invention provides a transceiver including a ball lens, an optical filter disposed within the ball lens for transmitting a first optical signal at a first wavelength and for reflecting a second optical signal at a second wavelength, a light source for emitting the first optical signal to the ball lens, a receiver for receiving the second optical signal from the ball lens, and an input/output port optically coupled with the ball lens for at least one of receiving the first optical…
Integrated micro-optic architecture for combining and depolarizing plural polarized laser beams
Granted: December 19, 2002
Application Number:
20020191290
A multimode laser beam depolarization and combining architecture integrates a combiner for polarized multimode light beams with a multimode beam depolarizer, that produces a composite depolarized output beam optimized for application to a Raman optical amplifier. A high-order depolarizing 45° waveplate is used to effectively depolarize multimode laser beams produced by a Fabry-Perot (FP) laser. The high-order 45° waveplate has a length that achieves multi mode…
Method and apparatus for amplifying an optical signal
Granted: December 19, 2002
Application Number:
20020191277
A method and apparatus for amplifying an optical signal includes an amplification scheme that combines Raman amplification (RA) with a semiconductor optical amplifier (SOA) to achieve a wider bandwidth, flatter gain spectrum, and higher gain than either RA or SOA is able to achieve independently. The SOA is typically a conventional SOA selected to have a negatively sloped response, whereas the RA stage typically includes a distributed Raman amplifier pumped with a wavelength and power so…
Multi-cavity resonator interferometer
Granted: December 5, 2002
Application Number:
20020180981
Interleavers, based on a Michelson interferometer with a Gires-Tournois (GT) etalon in each arm, are becoming popular in the filtering of light in the fiber optics telecommunications industry. As the channel spacing becomes closer together, e.g. 50 GHz or 25 GHz, dispersion compensation becomes an important factor in the choice and design of a system. The present invention solves the problem of increased chromatic dispersion by utilizing multi-cavity Gires-Tournois (MCGT) etalons,…
Method and apparatus for measuring chromatic dispersion in optical fibers
Granted: November 28, 2002
Application Number:
20020176070
An apparatus for measuring chromatic dispersion in a waveguide uses a CW laser probe signal and a modulated pump signal which are coupled together into a waveguide. The modulated pump signal causes spatial and temporal Raman gain modulation of the probe signal. The amplitude of the pump signal is modulated and the frequency response of the probe signal at the output end of the waveguide is measured. The chromatic dispersion of the waveguide at a given wavelength is determined from the…
Dynamically tunable resonator for use in a chromatic dispersion compensator
Granted: November 28, 2002
Application Number:
20020176659
A tunable etalon for use in a dispersion compensator according to the present invention includes a Gires-Tournois (GT) etalon with a variably reflective front mirror section and a fixed back mirror section defining a resonance cavity therebetween. The front mirror section includes one or more tunable gaps formed between pairs of partially reflective mirrors and filled with a material with a variable index of refraction, e.g. liquid crystal. Due to the variability of the material's…
Variable optical attenuator
Granted: November 28, 2002
Application Number:
20020176687
The invention provides a variable optical attenuator or array with low PDL by using an embedded polymer channel waveguide with a plurality of resistive heaters fabricated on the top cladding of the polymer waveguide. The resistive heaters create a strong thermal gradient in the polymer layer stack which is associated with a strong refractive index gradient with the lowest refractive index under the heater. This refractive index gradient causes the optical mode in the channel to shift…
Solder bonding technique for assembling a tilted detector chip
Granted: November 21, 2002
Application Number:
20020170943
A method for solder bonding a photodiode or an array of photodiodes to a substrate, the photodiode(s) tilted at a predetermined angle, uses a pair solder bumps placed on a photodiode chip opposite a corresponding pair of asymmetric solder pads placed on the substrate. When the photodiode chip is placed on the substrate, with the solder bumps therebetween, the solder is melted and undergoes a reflow over the surface of the pads. This causes the chip to tilt to one side about the axis…
Low dispersion interleaver
Granted: November 21, 2002
Application Number:
20020171908
The present invention relates to an interferometer useful in the interleaving and de-interleaving of optical wavelength channels. Typically the invention comprises a beamsplitter and two resonators, e.g. GT etalons or ring resonators. The beamsplitter splits an input beam of light into a first sub-beam directed to follow a first path and a second sub-beam directed to follow a second path. The first resonator has a first effective cavity length and receives the first sub-beam. The second…
Stress free and thermally stabilized dielectric fiber
Granted: November 21, 2002
Application Number:
20020171936
A multilayer optical interference filter having a multiplicity of optical cavities separated by a dielectric reflector stacks to achieve either a very narrow passband region or sharp transition between the passband and reflective region is substantially free of stress to preserve the desired optical performance upon fabrication into miniature discrete filter elements. The substantial stress reduction is achieved by removing the filter from the substrate used in the deposition process in…
Optical circulator
Granted: November 14, 2002
Application Number:
20020168128
An optical circulator with a first, second, third, and fourth port. The second and third port are disposed to receive polarized light entering the circulator as unpolarized light from the first port. The fourth port is disposed to receive unpolarized light entering the circulator as polarized light from the second and third port. The circulator comprises a beam-splitting and -combining element for separating and combining mutually orthogonal polarizations and a non-reciprocal…
Optical performance monitor
Granted: November 14, 2002
Application Number:
20020168142
An optical performance monitor having a tunable fiber grating sandwiched between the first and second reflective surfaces of a fiber etalon provides high sensitivity, while simultaneously monitoring an optical data signal. Individual channels within the optical data signal are monitored by tuning the fiber grating over the wavelength range of the optical data signal to measure an intensity of each channel. As the tunable grating scans the wavelength range of interest, it simultaneously…
