Abstract:
An apparatus and method are provided for manipulating light beams propagated through PLCs in free space. Light beams propagated in through an input/output waveguide of a PLC are propagated through a waveguide array to generate a phased array output at an edge facet of the PLC. The phased array output at the edge facet is spatially Fourier transformed by a lens in free space, generating a spectrally resolved image at the back focal plane of the lens. The spectrally resolved image is reflected, at least in part, by a reflector device and coupled into a desired waveguide array of a PLC to produce a desired output.
Abstract:
A low-loss integrated optical coupler includes at least three substantially similar optical couplers, adjacent ones of the optical couplers interconnected via at least one set of waveguides, each of the sets of waveguides comprising a path-length difference between the waveguides therein. In one embodiment of the present invention, the multi-section optical coupler comprises at least two arms and the path-length differences are adjustable such that signals traversing the at least two arms undergo a relative phase shift, such that a desired output power splitting ratio for the multi-section optical coupler is achieved. Alternatively, the optical coupler is implemented in an inventive optical device that functions at least, as an optical switch or an optical splitter.
Abstract:
The inventor proposes herein a novel optical monitor requiring only a single fiber-coupled photodetector. In one embodiment of the present invention, the optical monitor further includes an optical coupler for tapping a portion of an optical signal, a tunable filter for filtering the tapped optical signal at a predetermined frequency, and a Faraday rotator mirror for removing any polarization dependence of the tapped optical signal and for reflecting the filtered optical signal back through the tunable filter and the coupler. Subsequently, the photodetector of the optical monitor measures the power of the filtered optical signal. The optical spectrum of the optical signal is thus measured by scanning the tunable filter across the band of the optical signal and measuring the power of the optical signal as a function of the optical frequency of the tunable filter.
Abstract:
Timing alignment between a pulse carver (i.e., intensity modulator) and a phase modulator, e.g., in a return-to-zero (RZ) differential phase-shift keying (DPSK) optical transmitter, is monitored by filtering a signal from the transmitter and measuring the power of the filtered signal. In certain embodiments, the filter has a birefringent device (such as a polarization-maintaining fiber) and a polarizer. The polarizer may be a rotating polarizer with a rotating quarter-wave plate in front of it. In other embodiments, the filter is a periodic filter such as a Mach-Zehnder interferometer or an etalon filter. Regardless, the measured power may be used to generate control signals used to variably delay the signals that drive the phase modulator and/or the pulse carver to compensate for detected misalignment. The measured power may also be used to monitor the bit-error-rate degradation caused by timing misalignment between the pulse carver and the phase modulator.
Abstract:
An optical device includes an input/output optical coupler, a waveguide and a waveguide fragment. The optical coupler is configured to separate a received optical signal into first and second signal components. The waveguide is connected to the optical coupler and configured to propagate the first signal component via a first propagation mode. The waveguide fragment is located adjacent to the first waveguide and is configured to couple light from the first waveguide that propagates therein by a different second propagation mode.
Abstract:
Various exemplary embodiments relate to an optical waveguide coupler including: a first optical waveguide including a first area and a tapered area having a tapered width; a second optical waveguide including a first area and a tapered area having a tapered width; wherein the first area of the of the second optical waveguide overlaps the tapered area of the first optical wave guide, and wherein the tapered area of the second optical waveguide overlaps the first area of the first optical waveguide.
Abstract:
An optical device includes an array of optical grating couplers and a plurality of single-core fiber couplers located over a planar substrate. The optical grating couplers of the array are located to optically couple in a one-to-one manner to optical cores of a multi-core fiber or optical cable having an end located adjacent to the surface. Each single-core fiber coupler includes a planar optical waveguide connecting a corresponding one of the optical couplers of the array to an edge of the substrate.
Abstract:
A proposed integrateable optical interleaver includes an input Y-branch coupler and at least two multi-section optical couplers. The multi-section optical couplers of the interleaver include at least three substantially similar optical couplers, adjacent ones of the optical couplers interconnected via at least one set of waveguides. The interleaver of the present invention comprises a highly compact and fabrication-robust form that is capable of being integrated onto a single planar lightwave circuit.
Abstract:
A planar lightwave circuit coupler including first and second waveguides with curved coupling portions having radii of curvature selected such that the coupler has a splitting ratio that is substantially wavelength and polarization insensitive.
Abstract:
A colorless, waveguide-grating-router-based tunable dispersion compensator includes a planar lightwave circuit and a deformable mirror, optically coupled to each other by a plano-cylindrical glass lens such that a fast tuning speed and single-knob dispersion adjustment are obtained. In a further aspect of the present invention, the waveguide-grating router is pinched, symmetrical about its center line, and has a half-wave plate inserted therein to provide polarization independence. In a still further aspect of the present invention, the deformable mirror includes, reflective film attached to opposing piezo-electric actuators.