Abstract: Disclosed herein are various embodiments of an optical cross-connect switch in which optical beamforming is used to generate desired (e.g., technically beneficial) beam profiles at the beam-steering element of the switch. An example beam profile that can be generated in this manner is a substantially rectangular beam profile generated from an input optical beam having a substantially Gaussian beam profile. The use of rectangular beam profiles may be beneficial because such beam profiles can be used to increase the optical fill factor of the beam-steering element of the switch, thereby enabling the switch to have a higher number of optical ports and/or a lower cost per optical port than comparable conventional optical cross-connect switches. In an example embodiment, the disclosed optical cross-connect switch can be used to implement a wavelength-selective optical router.

Abstract: An optical data transmitter includes vertical cavity surface-emitting lasers and an all-optical spatial mode multiplexer. Each vertical cavity surface-emitting laser is configured to output a data modulated optical carrier at a center wavelength of less than one micrometer. The all-optical spatial mode multiplexer has an optical output and optical inputs. Each vertical cavity surface-emitting lasers is optically connected to one or more of the optical inputs of the all-optical spatial mode multiplexer. The all-optical spatial mode multiplexer is configured to cause at least two of the vertical cavity surface-emitting lasers to excite linearly independent combinations of one or more optical spatial propagating modes of an optical fiber in response to the optical output being coupled to a near end of the optical fiber.

Abstract: An optical line card includes a plurality of coherent receivers and a plurality of optical modulators. The coherent receivers are each configured to receive a corresponding channel of a received optical superchannel. The optical modulators are each configured transmit a corresponding channel of a transmitted optical superchannel. Each of a plurality of optical splitters is configured to receive a corresponding one of a plurality of unmodulated optical signals from an optical source external to the line card. Each splitter directs a first portion of light received by that splitter to a corresponding one of the coherent receivers, and a second portion of light received by that splitter to a corresponding one of said optical modulators.

Abstract: An optical line card includes a plurality of coherent receivers and a plurality of optical modulators. The coherent receivers are each configured to receive a corresponding channel of a received optical superchannel. The optical modulators are each configured transmit a corresponding channel of a transmitted optical superchannel. Each of a plurality of optical splitters is configured to receive a corresponding one of a plurality of unmodulated optical signals from an optical source external to the line card. Each splitter directs a first portion of light received by that splitter to a corresponding one of the coherent receivers, and a second portion of light received by that splitter to a corresponding one of said optical modulators.

Abstract: We disclose a vertical-cavity surface-emitting laser (VCSEL) whose optical resonator can support multiple transverse resonator modes. The VCSEL has a plurality of electrodes that can apply individually controllable electrical currents to the active semiconductor region of the optical resonator and be configured to excite, e.g., a single selected transverse resonator mode or a desired linear combination of transverse resonator modes. In some embodiments, the VCSEL's optical resonator may have an effective lateral geometric shape that causes the excitable transverse resonator modes to correspond to the waveguide modes of a cylindrical optical fiber.

Abstract: An optical apparatus includes a front optics section and a spectrometer section. The front optics section includes a spot de-multiplexer configured to receive a plurality of multi-mode optical signals each having a plurality of modal components, and to output in a linear array of a corresponding plurality of optical beams for each multimode optical signal. The spectrometer section includes a wavelength steering element configured to separate each of the optical beams into a plurality of wavelength channels. A fiber steering element is configured to steer the wavelength channels between the optical beams.

Abstract: An apparatus includes a plurality of VCSELs, a master laser, one or more electrical drivers, and an optical combiner. The master laser is configured to transmit laser light to the VCSELs to optically lock wavelengths of the VCSELs. The one or more electrical drivers are connected to directly electrically modulate the VCSELs in a manner responsive to one or more digital data stream. The optical combiner is configured to combine light received from, at least, a pair of the VCSELs into an optical carrier with a substantially phase digital data modulation.

Abstract: An apparatus includes an optical transmitter having a plurality of optical data modulators and an end-face coupler. Each of the optical data modulators is configured to output a corresponding data-modulated optical carrier. The optical end-face coupler is configured to direct the data-modulated optical carriers into a pattern of light beams to illuminate an end-face of a multi-mode optical fiber with a pattern of light spots. The optical end-face coupler is configured to cause each of the data-modulated optical carriers to excite a set of orthonormal optical propagating modes of the multi-mode optical fiber. Some of the orthonormal optical propagating modes of the set have nontrivially differing intensity and/or phase profiles.

Abstract: An apparatus includes an all-optical transmission line having, at one wavelength, a pair of relatively orthogonal optical propagating modes whose local group velocities differ along a part of the all-optical transmission line. The all-optical transmission line is formed by a sequence of optically end-connected multi-mode fiber segments. The segments include, at least, 80% of the optical path length of the all-optical transmission line. Each segment is configured such that a differential group delay between the pair varies monotonically there along and changes by, at least, 200 pico-seconds thereon.

Abstract: A method forms an image with a reconfigurable array of mirrors. The method includes configuring the array by translating some of the mirrors such that distances of the mirrors of the array from a reference plane have a non-uniform spatial distribution. The method includes illuminating the configured array with a coherent light beam such that part of the light beam is reflected off the array and is projected on a planar viewing screen.

Abstract: An apparatus includes a multi-mode optical fiber having a selected plurality of optical propagating modes. The selected plurality may include only a proper subset of or may include all of the optical propagating modes of the multi-mode optical fiber. Each optical propagating mode of the selected plurality has a group velocity that varies over a corresponding range for light in, at least, one of the optical telecommunications C-band, the optical telecommunications L-band, and the optical telecommunications S-band. The ranges corresponding to different ones of the modes of the selected plurality are non-overlapping. The ranges of a group velocity-adjacent pair of the ranges are separated by a nonzero gap of less than about 10,000 meters per second.

Abstract: We disclose a vertical-cavity surface-emitting laser (VCSEL) whose optical resonator can support multiple transverse resonator modes. The VCSEL has a plurality of electrodes that can apply individually controllable electrical currents to the active semiconductor region of the optical resonator and be configured to excite, e.g., a single selected transverse resonator mode or a desired linear combination of transverse resonator modes. In some embodiments, the VCSEL's optical resonator may have an effective lateral geometric shape that causes the excitable transverse resonator modes to correspond to the waveguide modes of a cylindrical optical fiber.

Abstract: An optical data transmitter includes vertical cavity surface-emitting lasers and an all-optical spatial mode multiplexer. Each vertical cavity surface-emitting laser is configured to output a data modulated optical carrier at a center wavelength of less than one micrometer. The all-optical spatial mode multiplexer has an optical output and optical inputs. Each vertical cavity surface-emitting lasers is optically connected to one or more of the optical inputs of the all-optical spatial mode multiplexer. The all-optical spatial mode multiplexer is configured to cause at least two of the vertical cavity surface-emitting lasers to excite linearly independent combinations of one or more optical spatial propagating modes of an optical fiber in response to the optical output being coupled to a near end of the optical fiber.

Abstract: An apparatus includes an optical fiber bundle that includes a plurality of input optical fibers and a tapered segment. One end of each of the input optical fibers physically connects to a wide end of the tapered segment. The optical fiber bundle is an integral unit. The input optical fibers are multimode optical fibers. Fundamental optical propagating modes of at least two of the multimode optical fibers have different velocities.

Abstract: Disclosed herein are various embodiments of an optical cross-connect switch in which optical beamforming is used to generate desired (e.g., technically beneficial) beam profiles at the beam-steering element of the switch. An example beam profile that can be generated in this manner is a substantially rectangular beam profile generated from an input optical beam having a substantially Gaussian beam profile. The use of rectangular beam profiles may be beneficial because such beam profiles can be used to increase the optical fill factor of the beam-steering element of the switch, thereby enabling the switch to have a higher number of optical ports and/or a lower cost per optical port than comparable conventional optical cross-connect switches. In an example embodiment, the disclosed optical cross-connect switch can be used to implement a wavelength-selective optical router.

Abstract: An apparatus, e.g. an optical oscilloscope, includes an optical receiver front end, including an optical device, and an optical delay. The receiver front end is configured to receive at least one input optical signal and produce by the optical device at least first and second output optical signals. The receiver front end is further configured to gate said at least one input optical signal or said at least first and second output optical signals. An optical combiner is configured to combine said at least first and second output optical signals, and the optical delay is located in an optical path of said first optical output signal between said optical receiver front end and the optical combiner. An optical detector is configured to receive a combined optical signal from said optical combiner and to produce therefrom an analog-electrical signal representative of the combined optical signal.

Abstract: An optical amplifier includes a multi-mode pump laser module, a multi-mode waveguide, a multi-mode to multiple single-mode fiber converter module and a plurality of single-mode cores. The multi-mode pump laser module emits pump light having a plurality of modes to the multi-mode fiber or waveguide. The multi-mode waveguide propagates the emitted pump light to the converter module. The converter module receives the pump light and distributes the pump light approximately uniformly to a plurality of single-mode cores.

Abstract: An optical line card includes a plurality of coherent receivers and a plurality of optical modulators. The coherent receivers are each configured to receive a corresponding channel of a received optical superchannel. The optical modulators are each configured transmit a corresponding channel of a transmitted optical superchannel. Each of a plurality of optical splitters is configured to receive a corresponding one of a plurality of unmodulated optical signals from an optical source external to the line card. Each splitter directs a first portion of light received by that splitter to a corresponding one of the coherent receivers, and a second portion of light received by that splitter to a corresponding one of said optical modulators.

Abstract: An apparatus, e.g. an optical oscilloscope, includes an optical receiver front end, including an optical device, and an optical delay. The receiver front end is configured to receive at least one input optical signal and produce by the optical device at least first and second output optical signals. The receiver front end is further configured to gate said at least one input optical signal or said at least first and second output optical signals. An optical combiner is configured to combine said at least first and second output optical signals, and the optical delay is located in an optical path of said first optical output signal between said optical receiver front end and the optical combiner.

Abstract: A photonic lantern spatial multiplexer that provides mode selectivity includes a multimode optical waveguide and a plurality of single mode optical waveguides. The single mode cores of the single mode optical waveguides merge with the multimode core of the multimode optical waveguide. At least two of the single mode cores have different respective single mode effective refractive indexes.