Abstract: Consistent with the present disclosure, a photonic integrated circuit (PIC) is provided that has 2 N channels (N being an integer). The PIC is optically coupled to N optical fibers, such that each of N polarization multiplexed optical signals are transmitted over a respective one of the N optical fibers. In another example, each of the N optical fibers supply a respective one of N polarization multiplexed optical signals to the PIC for coherent detection and processing. A multiplexer and demultiplexer may be omitted from the PIC, such that the optical signals are not combined on the PIC. As a result, the transmitted and received optical signals incur less loss and amplified spontaneous emission (ASE) noise. In addition, optical taps may be more readily employed on the PIC to measure outputs of the lasers, such as widely tunable lasers (WTLs), without crossing waveguides.

Abstract: Consistent with the present disclosure, a photonic integrated circuit (PIC) is provided that has 2 N channels (N being an integer). The PIC is optically coupled to N optical fibers, such that each of N polarization multiplexed optical signals are transmitted over a respective one of the N optical fibers. In another example, each of the N optical fibers supply a respective one of N polarization multiplexed optical signals to the PIC for coherent detection and processing. A multiplexer and demultiplexer may be omitted from the PIC, such that the optical signals are not combined on the PIC. As a result, the transmitted and received optical signals incur less loss and amplified spontaneous emission (ASE) noise. In addition, optical taps may be more readily employed on the PIC to measure outputs of the lasers, such as widely tunable lasers (WTLs), without crossing waveguides.

Abstract: An apparatus having a first waveguide, a second waveguide, a third waveguide, a fourth waveguide, and a fifth waveguide is described. A symmetric coupler has a proximal end and a distal end. The proximal end of the symmetric coupler is coupled to and in optical communication with the first waveguide and the second waveguide. The distal end of the symmetric coupler is coupled to and in optical communication with the fourth waveguide. An asymmetric coupler has a proximal end and a distal end. The asymmetric coupler is in a cascaded configuration with the symmetric coupler. The cascaded configuration has the proximal end of the asymmetric coupler coupled to and in optical communication with the fourth waveguide and the third waveguide. The distal end of the asymmetric coupler is coupled to and in optical communication with the fifth waveguide.

Abstract: An apparatus having a first waveguide, a second waveguide, a third waveguide, a fourth waveguide, and a fifth waveguide is described. A symmetric coupler has a proximal end and a distal end. The proximal end of the symmetric coupler is coupled to and in optical communication with the first waveguide and the second waveguide. The distal end of the symmetric coupler is coupled to and in optical communication with the fourth waveguide. An asymmetric coupler has a proximal end and a distal end. The asymmetric coupler is in a cascaded configuration with the symmetric coupler. The cascaded configuration has the proximal end of the asymmetric coupler coupled to and in optical communication with the fourth waveguide and the third waveguide. The distal end of the asymmetric coupler is coupled to and in optical communication with the fifth waveguide.

Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.

Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.

Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.

Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.

Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.

Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.

Abstract: A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.

Abstract: Monolithic photonic integrated circuits (PICs) utilize forward error correction (FEC) joint encoder or plural encoders or a joint decoder or plural decoders.

Abstract: A monolithic optical transmitter photonic integrated circuit (TXPIC) comprises a plurality of integrated modulated sources which, when all operated at constant current, display a power output that varies as a function of array position similar to a quadratic-shaped curve and, further, forming an array of signal channels each having a different wavelength output. An optical combiner/decombiner is integrated in the circuit and has at least one free space region with a plurality of ordered bands along its edge where the zero order band is substantially at a longitudinal centerline of the free space region and where, on either side of this band, is a first order band followed by additional higher order bands.

Abstract: A monolithic photonic integrated circuit (PIC) chip where the active waveguide cores of the modulated sources of the PIC are multiple quantum wells (MQWs) and the passive waveguide cores of an optical combiner are a bulk layer or material. The cores of the waveguide cores may be a quaternary such as InGaAsP or InAlGaAs.

Abstract: Cleaved grooves, also referred to herein as “cleave streets”, are formed exclusively in a wafer passivation layer overlaying a wafer to provide for correctly aligned and sharp cleaves prior to singulation of the wafer into separate die or chips.

Abstract: A photonic integrated circuit that includes a plurality of active and passive components on a substrate where one of the components is an optical combiner/decombiner having at least one free space coupler region and a plurality of longitudinal ridge waveguides each extending in the circuit from a first region of the waveguide and coupled at a second region of the waveguide at the free space coupler region. A first dielectric layer formed over the ridge waveguides and the free space coupler region. The first dielectric layer monotonically increases in cross-sectional thickness from the waveguide first region to the second region to reduce signal insertion losses in transitioning from the ridge waveguides to the free space coupler region. The first dielectric layer may be covered with a second passivation layer. The first dielectric layer may be SiOx, SiNx or SixONy and the second passivation layer may be BCB, ZnS or ZnSe.

Abstract: A method for reducing insertion loss in a transition region between a plurality of input or output waveguides to a free space coupler region in a photonic integrated circuit (PIC) includes the steps of forming a passivation layer over the waveguides and region and forming the passivation overlayer such that it monotonically increases in thickness through the transition region to the free space coupler region.

Abstract: Disclosed is a method of adjusting a center channel wavelength of a group of channel wavelengths from of a plurality of modulated sources, integrated in a photonic integrated circuit (PIC), relative to the center of a wavelength passband of an optical combiner, such as an arrayed waveguide array (AWG), also integrated in the photonic integrated circuit (PIC) and optically coupled to outputs from the modulated sources.

Abstract: An optical transport network comprises a monolithic transmitter photonic integrated circuit (TxPIC) InP-based chip and a monolithic receiver photonic integrated circuit (RxPIC) InP-based chip.

Abstract: An InP-based photonic integrated circuit (PIC) includes an optical passive element in the circuit with no bias current applied to such an element. A passivation cladding layer overlies a surface of the optical passive element where the passivation layer comprises benzocyclobutene polymer or BCB.