Unlatching mechanism for an optical transceiver
Granted: May 27, 2004
Application Number:
20040101257
The present invention relates to an optical transceiver unlatching device for disengaging the optical transceiver from a mounting cage found in a host computer device. The unlatching device converts rotational motion from a bail handle into reciprocating motion for a sliding latch member, which disengages spring fingers extending from the mounting cage from abutment surfaces formed in the sides of the optical transceiver. A return spring, extending between the sliding latch member and…
Laser diode driving circuit with safety feature
Granted: May 27, 2004
Application Number:
20040099788
The invention relates to a feedback loop for a laser diode driving circuit for ensuring that the laser diode generates optical power at a constant safe level. The feedback loop includes a monitor diode, which generates a monitor current Imon, and a set resistance for generating a set voltage based on the monitor current and the set resistance. The set voltage is compared with a reference voltage in an operational amplifier, which generates a control signal for controlling the laser diode…
Wavelength tunable add-drop optical filter
Granted: May 20, 2004
Application Number:
20040096148
A wavelength-tunable add/drop device for adding or dropping n channels having different center wavelengths is disclosed. A first multicavity variable optical filter for selectably operable to passing one channel while reflecting n−1 other channels depends upon a location where light is launched into an end of the multicavity optical filter. A broadband optical reflector is disposed directly adjacent to the multicavity variable optical filter and disposed between planes coincident…
Optical channel monitoring device
Granted: May 20, 2004
Application Number:
20040096212
An apparatus for measuring optical performance of a plurality of channels within an input optical multi-channel signal employs at least one optical interleaver to deinterleave the input signal into a plurality of channel subsets, each channel subset having a greater channel spacing than the input multi-channel signal, and a switch for sequentially submitting the deinterleaved subsets to an optical performance monitor (OPM). The design allows for relaxed specification of the OPM, e.g. its…
Transmitter optical sub-assembly
Granted: May 13, 2004
Application Number:
20040091268
The invention relates to a transmitter optical sub-assembly (TOSA) for use in high data rate (10 Gb/s or higher) small form factor transceivers. A flexible cable electrical connector, a ceramic feedthrough, and a differential drive disposed adjacent the laser result in improved optical eye-diagrams with increased design margin. A heat spreader incorporated in the housing of the TOSA ensures constant performance at the high data rates.
Etalon having a self-supporting thin film
Granted: April 15, 2004
Application Number:
20040070833
The invention provides a substantially athermal etalon. In one embodiment, the multi-cavity etalon includes at least one free-standing multi-layer thin film and is rendered thermally stable through the use of the free-standing multi-layer film and spacers having predetermined thermal expansion coefficients. In another embodiment, the multi-cavity etalon is rendered thermally stable through the use of mixed spacers.
Multi-cavity optical filter
Granted: April 15, 2004
Application Number:
20040070834
The invention provides a multi-cavity filter, and in particular, a multi-cavity bandpass filter having a predetermined centre wavelength. The filter includes a plurality of cavities, each cavity including two partially reflecting films separated by a layer of dielectric material. The two partially reflecting layers are formed from layers of material having alternating high and low refractive indices. Each layer of dielectric material has a thickness that is an integral number of…
Launch interface electrode structure for suppressing coupling to substrate modes for electro-optic modulator
Granted: April 8, 2004
Application Number:
20040066549
A reduced size RF signal and ground electrode interface is configured to provide better field confinement of dominant coplanar waveguide mode in the propagation direction and reduce coupling RF energy into a substrate beneath the launch, while matching the impedance of the launch to both that of the coplanar microwave electrode structure overlying the interaction region, and that of the external RF connection to the launch. In ground plane embodiments, an underlying ground plane provides…
Sequential color recapture light system
Granted: April 1, 2004
Application Number:
20040062043
A light integrator is mounted in a housing or cover that allows aligning the light integrator relative to a color wheel or other sequential color element. In some embodiments, a plate is attached to one end of a light rod and supports the light rod in the cover in a cantilever fashion or in combination with other support. The light rod is aligned to a light source, such as a lamp, and then the color wheel is aligned to the output of the light rod without altering the relationship between…
Automatic raman gain control
Granted: March 18, 2004
Application Number:
20040052453
The invention relates to a method for automatic dynamic gain control in optical Raman amplifiers and an optical Raman amplifier adapted for the same. The present invention has found that in multiple pump Raman amplifiers a substantially linear relationship exists between total amplified signal power and pump power for each of different wavelength pumps, in order to maintain an original gain profile and gain levels for an optical link with a fully loaded channel configuration, in response…
Method and apparatus for orienting magnetic flakes
Granted: March 18, 2004
Application Number:
20040051297
Apparatus and related methods align magnetic flakes in a carrier, such as an ink vehicle or a paint vehicle to create optically variable images in a high-speed, linear printing operation. Images can provide security features on high-value documents, such as bank notes. Magnetic flakes in the ink are aligned using magnets in a linear printing operation. Selected orientation of the magnetic pigment flakes can achieve a variety of illusive optical effects that are useful for decorative or…
Optical monitoring circuit
Granted: February 26, 2004
Application Number:
20040036007
An optical monitoring circuit includes a photoelectric device such as a photo-detector that produces a signal in response to incident light thereon corresponding to a characteristic of the incident light such as intensity, or wavelength. A light source is disposed within the circuit for emitting a beam of light, a portion of which is to be incident upon the photoelectric device. The photoelectric device when reversed biased provides an output electrical signal from which the intensity of…
Wider dynamic range to a FBG stabilized pump
Granted: February 26, 2004
Application Number:
20040036956
The present application relates to a Raman amplifier having an increased dynamic range, and particularly for laser pump sources and a method of pumping Raman fiber amplifiers over a greater dynamic range. In a multi-channel optical system, optical amplifiers must be able to provide gains over a large dynamic range, which is determined by the distribution of node-to-node distances in the network, as well as the number of channels. The present invention has found that the dynamic range of…
Athermal interferometric device
Granted: February 5, 2004
Application Number:
20040021870
An athermal interferometric wavelocker is disclosed having a beam splitter combiner and a first arm of a first material having a first refractive index, a first length, and a first coefficient of expansion; and, a second arm of a second material having a second refractive index, a second length, and a second coefficient of expansion. The refractive indices, lengths and coefficients of expansion of the first arm and the second arm are selected to provide a substantially athermal structure…
Cascaded RZ and NRZ laser modulators having RZ/NRZ phase alignment bias control
Granted: January 15, 2004
Application Number:
20040008395
An optical transmitter architecture has a return-to-zero (RZ) laser modulator coupled in cascade with a non-return-to-zero (NRZ) laser modulator. Modulator bias and electronic phase delay bias are controlled using dither-based feedback, so as to align the phase of the RZ clock signal with that of the NRZ data. A first method uses an RZ quadrature AM dither or an RZ “hillclimber” bias dither, to apply a relatively low frequency dither signal to a variable RF delay for the RZ…
Articulated MEMS electrostatic rotary actuator
Granted: January 15, 2004
Application Number:
20040008400
A micro-electro-mechanical device designed such that the actuating means are only mechanically coupled to the optical components. The device includes a substrate, a mirror supported above the substrate, and a rotatory actuator also supported above the substrate. The mirror and actuator are mechanically coupled via a torsional coupling hinge such that the mirror can be angled and/or tilted by electrostatically driving the rotatory actuator. Advantageously, the micro-mirrors and actuator…
Method and apparatus for polarization mode dispersion monitoring in a multiple wavelength optical system
Granted: January 15, 2004
Application Number:
20040008991
The invention relates to the monitoring of polarization mode dispersion (PMD) using heterodyne detection for providing PMD compensation in optical networks, and an apparatus for monitoring PMD. In the present invention, a broadband PMD monitor is disclosed based on heterodyne detection with a tunable laser source which can be fed to a compensator such as an add/drop or other wavelength switch and polarization dependent attenuation means. A signal from a local oscillator is combined with…
Magnetic planarization of pigment flakes
Granted: January 15, 2004
Application Number:
20040009309
A magnetic field is applied to planarize magnetic pigment flakes relative to a surface. Pigment flakes, such as optically variable pigment flakes, are used in a variety of paints, inks, extrusions, powder coatings, and other forms for decorative and security applications. In many applications pigment flakes tend to align parallel to each other and to the surface to which they are applied. If the pigment flakes include a suitable magnetic structure, a magnetic field can be applied to…
Fiber depolarizer for fabry-perot laser diodes
Granted: January 8, 2004
Application Number:
20040005106
A Lyot depolarizer for depolarizing a laser with multiple longitudinal modes comprises two segments of PM fiber optimized for length as a function of the longitudinal mode spacing of the laser source, and not as taught in the prior art as a function of the laser coherence length. The present invention has found secondary coherence peaks in the coherence function of a multiple longitudinal mode source, which can significantly worsen the DoP if the PM fiber lengths are significantly…
Adherent all-gold electrode structure for lithium niobate based devices and the method of fabrication
Granted: January 1, 2004
Application Number:
20040002205
An electrode structure wherein galvanic corrosion at adhesion layers formed between electrodes and electronic or electro-optic substrates is eliminated. The electrode structure includes an electro-optic crystalline substrate, an amorphous layer disposed on the crystalline substrate, the amorphous layer having a composition substantially similar to a composition of the crystalline substrate, and a gold layer disposed directly on the amorphous layer. The amorphous layer is created using…
