Patent application number | Description | Published |
20080240733 | DISPERSION COMPENSATOR FOR FREQUENCY RESHAPED OPTICAL SIGNALS - An optical transmitter is disclosed including an optical signal source generating a frequency modulated signal encoding data. An optical spectrum reshaper is positioned to receive the frequency modulated signal and converts the frequency modulated signal into a reshaped signal having increased amplitude modulation relative to the frequency modulated signal. A third-order dispersive element is positioned to receive the reshaped signal and is adapted to impose third-order dispersion on the reshaped signal to generate a compensated signal having third-order dispersion effective to compensate for second-order dispersion caused by an optical fiber positioned between the optical transmitter and a receiver. | 10-02-2008 |
20080247763 | CHIRPED LASER WITH PASSIVE FILTER ELEMENT FOR DIFFERENTIAL PHASE SHIFT KEYING GENERATION - A method for generating D-N-PSK optical signals is disclosed wherein a laser is modulated to generate optical signal pairs including phase modulated and fixed phase portions, the phase modulated portions having a frequency encoding one or more data symbols and the fixed phase portion having a carrier frequency and a phase corresponding to the immediately preceding phase modulated portion. The output of the laser is passed through an optical spectrum reshaper having a transmission function chosen to attenuate a plurality of the phase modulated portions relative to the fixed phase portions. The phase modulated portions may have N frequency levels located on either side of the carrier frequency. One of the N frequency levels may be equal to the carrier frequency. | 10-09-2008 |
20090060526 | OPTICAL FM SOURCE BASED ON INTRA-CAVITY PHASE AND AMPLITUDE MODULATION IN LASERS - An optical transmitter is discloses having a gain section and a phase section. The phase section is modulated to generate a frequency modulated signal encoding data. The frequency modulated signal is transmitted through an optical spectrum reshaper operable to convert it into a frequency and amplitude modulated signal. In some embodiments, a driving circuit is coupled to the phase and gain sections is configured to simultaneously modulate both the phase and gain sections such that the first signal is both frequency and amplitude modulated. | 03-05-2009 |
20100098436 | METHOD AND APPARATUS FOR GENERATING SIGNALS WITH INCREASED DISPERSION TOLERANCE USING A DIRECTLY MODULATED LASER TRANSMITTER - An optical transmitter is disclosed wherein a signal processor receives a data stream and outputs a drive signal for a laser, where the drive signal encodes each bit of the data stream according to the values of adjacent bits effective to compensate for spreading of bits within the fiber. The output of the laser is input to an optical spectrum reshaper that outputs a signal having an enhanced extinction ratio. | 04-22-2010 |
20100329666 | THERMAL CHIRP COMPENSATION IN A CHIRP MANAGED LASER - Thermal chirp compensation in a chirp managed laser. In one example embodiment, a method for thermal chirp compensation in a chirp managed laser (CML) includes several acts. First, a first bias condition and temperature is selected. Next, a first thermal chirp compensation signal is generated. Then, the laser is driven by biasing a first input drive signal with the first thermal chirp compensation signal. Next, a second bias condition and temperature is selected. Then, a second thermal chirp compensation signal is generated. Finally, the laser is driven by biasing a second input drive signal with the second thermal chirp compensation signal. | 12-30-2010 |
20110170171 | OPTICAL DIFFERENTIAL PHASE-SHIFT KEYED SIGNAL DEMODULATOR - A phase-shift keyed signal demodulator is disclosed including a filter positioned to receive an input beam, a first photodiode positioned to receive light reflected from the filter, and a second photodiode positioned to receive light transmitted through the filter. A difference between outputs of the first and second photodiodes is interpreted to determine a data value encoded in the input beam. In another embodiment N filters receive inputs from a splitter and include transmission functions offset from one another. N pairs of photo diodes receive the transmitted and reflected beams from each filter and a decoder converts the outputs of the pairs of photodiodes to one or more data symbols. | 07-14-2011 |
20120251130 | THERMAL CHIRP COMPENSATION IN A CHIRP MANAGED LASER - Thermal chirp compensation in a chirp managed laser. In one example embodiment, a laser package including a laser and an optical spectrum reshaper configured to convert frequency modulated optical signals from the laser into an amplitude modulated optical signals is provided. A thermal chirp compensation device is in communication with the laser package and a laser driver. The thermal chirp compensation device includes means for generating bias condition and temperature specific thermal chirp compensation signals that each corresponds to a predetermined level of thermal chirp that is induced in the laser by operating the laser at a particular bias condition and temperature. | 10-04-2012 |
20120269523 | OPTICAL DIFFERENTIAL PHASE-SHIFT KEYED SIGNAL DEMODULATOR - A phase-shift keyed signal demodulator and method for demodulating is disclosed. An example demodulator includes N filters that receive inputs from a splitter and include transmission functions offset from one another. N pairs of photodiodes receive the transmitted and reflected beams from each filter and a decoder converts the outputs of the pairs of photodiodes to one or more data symbols. | 10-25-2012 |
20130094797 | Optical Transmitter With Tunable Chirp - An optical transmitter with chirp control includes an input polarizer having an input that receives an optical signal. The input polarizer polarizes the optical signal along an input polarization axis. A Mach-Zehnder modulator includes an optical input that is coupled to an output of the input polarizer and an electrical input that receives a modulation signal. The Mach-Zehnder modulator modulates the optical signal with the modulation signal. The input polarization axis of the input polarizer is chosen to achieve a desired chirp of the modulated optical signal. An output polarizer is coupled to the output of the Mach-Zehnder modulator. The output polarizer polarizes the modulated optical signal along a desired output polarization axis that combines TE and TM mode polarizations. | 04-18-2013 |
20140185139 | Birefringent Crystal Polarization Beam Splitter Assembly - An optical apparatus, comprising a polarization beam splitter (PBS) comprising a birefringent crystal having a front-end and a back-end, and an optical rotator positioned on the back-end of the birefringent crystal. Included is an optical apparatus comprising a PBS comprising a birefringent crystal and an optical rotator, wherein the PBS is configured to receive a multiplexed optical signal comprising a first polarized optical signal and a second polarized optical signal, wherein the second polarized optical signal is orthogonal to the first polarized optical signal, separate the first polarized optical signal from the second polarized optical signal using the birefringent crystal, and rotate the second polarized optical signal using the optical rotator such that the rotated second polarized optical signal is parallel to the first polarized optical signal. The PBS may further comprise only one lens, wherein the lens is positioned on the front-end of the birefringent crystal. | 07-03-2014 |
20140185253 | Miniature High Density Opto-Electronic Package - A method comprising coupling a circuit to an opto-electronic package via an anisotropic conductive film (ACF), wherein the opto-electronic package is configured to communicate electrical signals via the coupling at a maximum frequency of about 10 gigahertz (GHz) to about 40 GHz. An apparatus comprising, an opto-electronic package comprising a plurality of first electrodes, and a circuit comprising a plurality of second electrodes, wherein at least one of the first electrodes is coupled to at least one of the second electrodes via an ACF, and wherein the opto-electronic package is configured to communicate electrical signals via the coupling at a maximum frequency of about 10 GHz to about 40 GHz. | 07-03-2014 |