Tunable dispersion compensator configured for continuous setpoint control
Granted: December 4, 2012
Patent Number:
8326153
A tunable dispersion compensator (TDC) is tuned from a first dispersion setpoint to a second dispersion setpoint while maintaining continuity of the dispersion. The dispersion tuning follows a pre-determined trajectory in the time domain, so that continuity of the optical dispersion across the channel optical bandwidth is maintained while minimizing all other TDC-induced optical impairments during a tuning period.
Low creep metallization for optoelectronic applications
Granted: November 27, 2012
Patent Number:
8319236
A metallization on a semiconductor substrate is disclosed in the form of a laminate comprising a plurality of layers of a “conducting” metallization for providing electrical conductivity, interspersed with a plurality of layers of another metallization. By providing many layers the thickness of each individual layer can be reduced. Reduction in thickness of each layer leads to a reduction in grain size and a consequent reduction in creep over the lifetime of a device.
High power semiconductor laser diodes
Granted: November 27, 2012
Patent Number:
8320419
A high power laser source comprises a bar of laser diodes having a first coefficient of thermal expansion CTEbar on a submount having a second coefficient CTEsub and a cooler having a third coefficient CTEcool. The submount/cooler assembly shows an effective fourth coefficient CTEeff differing from CTEbar. This difference leads to a deformation of the crystal lattice of the lasers' active regions by mechanical stress. CTEeff is selected to be either lower than both CTEbar and CTEcool or…
Delay line interferometer with liquid crystal tuning element
Granted: October 23, 2012
Patent Number:
8294980
A delay line interferometer is configured with a liquid-crystal (LC) tuning element as a phase modulator for demodulating a phase-modulated input signal. The LC tuning element allows for quickly tuning the phase difference between two optical signals separated from the phase-modulated input signal, so that the two optical signals can be coherently recombined to interfere with each other and produce one or more intensity-modulated optical signals. In some embodiments, the LC tuning…
Optical amplifiers using switched filter devices
Granted: October 23, 2012
Patent Number:
8294981
Described are Gain Flattening Filters (GFFs) implemented using mechanical translating assemblies to move selected thin film Gain Attenuating Filters (GAFs), and combinations of selected GAFs, into or out of the output path from an optical amplifier. The GAFs may be used singly, or in combinations that synthesize many target filter characteristics. The GFF is primarily adapted for WDM systems operating with a wavelength range of approximately 1520 nm to 1620 nm. Several embodiments are…
Tunable laser
Granted: October 23, 2012
Patent Number:
8295315
The present invention concerns tunable distributed Bragg reflector (DBR) semiconductor lasers, in particular a DBR laser with a branched optical waveguide 5 within which a plurality of differently shaped lasing cavities may be formed, and a method of operation of such a laser. The laser may comprise a phase control section (418), gain section (420, 422), a sampled grating DBR (412) giving a comb-line spectrum and two tunable, chirped DBRs (414, 416) for broadband frequency training and a…
Semiconductor laser device
Granted: September 18, 2012
Patent Number:
8270446
High performance and high reliability of a semiconductor laser device having a buried-hetero structure are achieved. The semiconductor laser device having a buried-hetero structure is manufactured by burying both sides of a mesa structure by a Ru-doped InGaP wide-gap layer and subsequently by a Ru-doped InGaP graded layer whose composition is graded from InGaP to InP, and then, by a Ru-doped InP layer. By providing the Ru-doped InGaP graded layer between the Ru-doped InGaP wide-gap layer…
High power top emitting vertical cavity surface emitting laser
Granted: August 21, 2012
Patent Number:
8247252
A method of adjusting a power density in a laser device including a VCSEL array providing an increased power density at a high wall-plug efficiency in that the lateral design parameters are appropriately selected on the basis of a relationship that has been established for a specified vertical design, a corresponding process technology and specified operating conditions. Thus, the total output power, the power density, and the efficiency may be optimized independently from other design…
Continuously tunable optical dispersion compensation synthesizers using cascaded etalons
Granted: July 3, 2012
Patent Number:
8213073
Described is a method for designing individual stages of a multiple cascaded etalon TDC device to allow continuous thermo-optic tuning over a desired range without inducing incremental signal distortion due to uncontrolled and unpredictable dispersion of the TDC during tuning. This allows the signal to transmit without encountering periods of incremental distortion or dark spots. The method includes prior knowledge of each etalon stage, after full assembly, for spectral group delay…
Optical communications
Granted: July 3, 2012
Patent Number:
8213806
A method of transmitting a plurality n data streams comprises modulating an optical carrier using differential M-ary phase shift key (DMPSK) signalling in which M=2n. Advantageously the method comprises using differential quaternary phase shift keying in which n=2. A particular advantage of the method of the present invention is that since the data is differentially encoded in the form of phase changes rather than absolute phase values this enables the modulated optical carrier to be…
Electro-optic device packages
Granted: June 26, 2012
Patent Number:
8206042
A package design for electro-optic devices has been developed in which the substrate supporting the electro-optic element serves also as the base of the device housing. The electro-optic element is flip-chip bonded to the substrate. In a preferred embodiment the substrate is a multi-level wiring board.
High extinction ratio liquid crystal optical switch
Granted: June 19, 2012
Patent Number:
8203691
An optical switch for performing high extinction ratio switching of an optical signal includes a beam polarizing element and one or more optical elements. The optical elements are configured to direct an optical signal along a first or second optical path based on the polarization state of the optical signal as it passes through the optical elements. The optical switch performs high extinction ratio switching of the optical signal by preventing unwanted optical energy from entering an…
Laser light source and method of operating the same
Granted: June 12, 2012
Patent Number:
8199784
A laser light source comprises a semiconductor laser adapted for pulsed operation, a partially transmitting wavelength selective light reflector. The semiconductor laser comprises a front facet and a back facet. The front facet and the back facet define an internal laser cavity. The internal laser cavity comprises a laser active medium. The partially transmitting wavelength selective light reflector has a peak reflectivity within a gain bandwidth of said laser active medium. The…
Demodulation of an optical carrier
Granted: June 12, 2012
Patent Number:
8200099
A method of transmitting a plurality n data streams comprises modulating an optical carrier using differential M-ary phase shift key (DMPSK) signaling in which M=2n. Advantageously the method comprises using differential quaternary phase shift keying in which n=2. A particular advantage of the method of the present invention is that since the data is differentially encoded in the form of phase changes rather than absolute phase values this enables the modulated optical carrier to be…
System of method for dynamic range extension
Granted: May 8, 2012
Patent Number:
8175127
The present invention generally relates to the operation of optical network equipment such as optical amplifiers. In one aspect, a method of operating an optical amplifier is provided such that output of the optical amplifier avoids the effects of operating an optical gain medium in a non-linear (kink) region of an L-I curve. The method generally includes operating an optical gain medium in a fully off state or fully on state above the kink region with a PWM signal. In another aspect,…
Bragg reflector grating
Granted: April 17, 2012
Patent Number:
8160410
A Bragg reflector grating comprises a plurality of chirped grating sections (65-72), in which at least a first chirped grating section and a second chirped grating section have differing ranges of grating pitches. The combined range of grating pitches provided by the first and second chirped grating sections includes at least one discontinuity, such that the first and second chirped grating sections have one or more grating pitches in common and/or there are one or more ranges of grating…
Liquid crystal optical device configured to reduce polarization dependent loss and polarization mode dispersion
Granted: March 27, 2012
Patent Number:
8144276
An LC-based optical device compensates for differences in optical path lengths of polarization components of input beam. As a result, PDL and PMD of the optical device are reduced. The compensation mechanism may be a glass plate that is disposed in an optical path of a polarization component so that the optical path length of that polarization component can be made substantially equal to the optical path length of the other polarization component that traverses through a half-wave plate.…
High power semiconductor opto-electronic device
Granted: February 7, 2012
Patent Number:
8111727
Semiconductor laser diodes, particularly broad area single emitter (BASE) laser diodes of high light output power, are commonly used in opto-electronics. Light output power and stability of such laser diodes are of crucial interest and any degradation during normal use is a significant disadvantage. The present invention concerns an improved design of such laser diodes, the improvement in particular significantly minimizing or avoiding degradation of such laser diodes at very high light…
Fiber lens assembly for optical device
Granted: January 10, 2012
Patent Number:
8094982
A fiber lens assembly is configured to optically couple an optical fiber to a signal processing device having free-space optical elements. The fiber lens assembly includes a diverging lens having a focal length that may be around 2 to 6 times the diameter of the optical fiber core. Sensitivity of the fiber lens assembly to angular misalignment and positional displacement is reduced by coupling the optical fiber to the signal processing device using a diverging lens rather than a…
Optoelectronic device and method of operating optoelectronic device
Granted: December 20, 2011
Patent Number:
8081671
The invention provides an optoelectronic device combining a vertical cavity surface emitting laser (VCSEL) and a photodetector for monitoring the output power of the vertical cavity surface emitting laser. To improve the signal-to-noise ratio of the photodetector, a light deflector is interposed between the photodetector and the VCSEL.
