Abstract: The present invention provides a hybrid integrated optical module having a high coupling efficiency by suppressing a connection loss between waveguides. A hybrid integrated optical module according to an embodiment of the present invention is an optical module which integrates a semiconductor chip and a PLC chip. The semiconductor chip has a semiconductor waveguide and is mounted on a Si bench. The PLC chip includes a PLC substrate and an optical waveguide formed on the PLC substrate. An end face of the semiconductor chip protrudes from an end face of the Si bench toward the PLC chip side by a protrusion amount X. Gap adjustment (adjustment of a distance D) between the semiconductor waveguide and the optical waveguide becomes possible by setting a position where the end face of the semiconductor chip is brought into contact with an end face of the PLC chip to be a reference position (zero point).

Abstract: Two Mach-Zehnder optical interferometer circuits 13a and 13b are accurately point-symmetrically connected to each other to form a first point-symmetrically connected optical interferometer circuit 5 constituting a light input side circuit 1. Optical signals having a plurality of wavelengths are input to a light input terminal 17. A second point-symmetrically connected optical interferometer circuit 7 having the same functional structure as the first point-symmetrically connected optical interferometer circuit 5 is connected to a through port 18, which is an output terminal of the light input side circuit 1, as a first light output side circuit 2. A cross port 19, which is the other output terminal of the light input side circuit 1, is connected to a second light output side circuit 3 having at least one of Mach-Zehnder optical interferometer circuits 13c and 13d whose transmittance characteristics are different from those of the Mach-Zehnder optical interferometer circuits 13a and 13b.

Abstract: An arrayed waveguide grating includes: at least one first waveguide; a first slab waveguide connected to the at least one first waveguide; a plurality of second waveguides; a second slab waveguide connected to the plurality of second waveguides; and an arrayed waveguide. The arrayed waveguide includes: M channel waveguides connected between the first slab waveguide and the second slab waveguide, wherein M is a natural number; and a phase correcting portion configured to provide a predetermined phase to at least a part of the M channel waveguides by one or both of a width and a length of the at least the part of the M channel waveguides being changed.

Abstract: A delay-line demodulator for demodulating a differential quadrature phase shift keying (DQPSK) signal is provided. The demodulator includes two Mach-Zehnder interferometers individually comprising two waveguides having different lengths therebetween and through which a light signal branched from the DQPSK signal propagates, respectively. A phase of the light signal propagating at one of the waveguides is delayed as compared to a phase of the light signal propagating at another one of the waveguides, wherein a divergence amount of polarization is adjusted by driving sets of heaters that are facing each other and sandwiching a half wavelength plate therebetween.

Abstract: Two Mach-Zehnder optical interferometer circuits 13a and 13b are accurately point-symmetrically connected to each other to form a first point-symmetrically connected optical interferometer circuit 5 constituting a light input side circuit 1. Optical signals having a plurality of wavelengths are input to a light input terminal 17. A second point-symmetrically connected optical interferometer circuit 7 having the same functional structure as the first point-symmetrically connected optical interferometer circuit 5 is connected to a through port 18, which is an output terminal of the light input side circuit 1, as a first light output side circuit 2. A cross port 19, which is the other output terminal of the light input side circuit 1, is connected to a second light output side circuit 3 having at least one of Mach-Zehnder optical interferometer circuits 13c and 13d whose transmittance characteristics are different from those of the Mach-Zehnder optical interferometer circuits 13a and 13b.

Abstract: A multiplexer/demultiplexer includes: a waveguide chip including a first chip and a second chip that are divided by a plane and obtained by cutting, together with a substrate, in a direction crossing an optical axis, a first slab waveguide of an AWG including the first slab waveguide and a second slab waveguide that are formed on the substrate; a first base to which the first chip is fixed; a second base separated from the first base and to which the second chip is fixed; and a member that has one end fixed to the first base or chip and another end fixed to the second base or chip, in a state in which cut surfaces of the first and second chips face each other, and that is configured to move the first base and the second base relatively to each other along the plane by expanding/contracting when temperature changes.

Abstract: An arrayed waveguide grating includes: at least one input waveguide; an input slab waveguide connected to the input waveguide; a plurality of output waveguides; an output slab waveguide connected to the output waveguides; and an arrayed waveguide. The arrayed waveguide includes: M channel waveguides connected between the input slab waveguide and the output slab waveguide; and a phase correcting portion configured to provide a predetermined phase to at least a part of the M channel waveguides by a form of the at least the part of the M channel waveguides being changed.

Abstract: An athermal AWG module 10 comprises: an AWG 11 having waveguides partially divided to separate a chip, separated chips being connected by a compensation plate 33 to achieve temperature-independence; an athermal AWG chip 12 having a substrate and the AWG 11 formed on the substrate; a package 13 having an opening 14 and accommodating the athermal AWG chip 12; and a cover for blocking the opening 14. The athermal AWG chip 12 is fully covered with a gelled refractive index matching agent 16 that is matched in refractive index to the waveguides of the AWG 11. As the gelled refractive index matching agent 16 is excellent in water resistance and hardly passes water, the adhesive agent for fixing the compensation plate 33 to the surfaces of the separated two chips is prevented from being deteriorated due to ingress of water, thereby enhancing the reliability.

Abstract: The present invention provides methods to control phase shift of delay demodulation devices to reduce Polarization Dependent wavelength (PD?) to be less than, for example, 0.5 GHz (i.e. 0.004 nm).

Abstract: There is provided a SSC chip whose yield may be improved and whose processing steps may be simplified as compare to those of a prior art PLC chip having a light waveguide circuit to which a spot-size converter (SSC) is added, a fiber array attached with the SSC chip, a PLC module attached with the SSC chip and a method for manufacturing the SSC chip. The SSC chip has four spot-size converters and is fabricated separately from a PLC chip. Each SSC has a straight waveguide having the same core width and height with an end of an input/output waveguide of the PLC chip, a horizontally tapered waveguide in which the core width is enlarged in a tapered shape in the horizontal direction from the core width of the straight waveguide, a vertically tapered waveguide in which the core height is enlarged in a tapered shape in the vertical direction from the core height of the horizontally tapered waveguide and a spot-size enlarged portion whose core width and core height are both enlarged.

Abstract: An optical integrated circuit includes a planar lightwave circuit, and a semiconductor element, which are fixed at one contact surface. A semiconductor optical amplifier (SOA) and a turnaround waveguide having a turnaround portion are formed on a semiconductor substrate. The turnaround waveguide is turned around on the second substrate and is connected to an output port of the SOA. An input port and an output port of the turnaround waveguide are optically coupled at the contact surface with an input port and an output port of the optical waveguides respectively.

Abstract: A delay-line demodulator for demodulating a differential quadrature phase shift keying (DQPSK) signal is provided. The demodulator includes two Mach-Zehnder interferometers individually comprising two waveguides having different lengths therebetween and through which a light signal branched from the DQPSK signal propagates, respectively. A phase of the light signal propagating at one of the waveguides is delayed as compared to a phase of the light signal propagating at another one of the waveguides, wherein a divergence amount of polarization is adjusted by driving sets of heaters that are facing each other and sandwiching a half wavelength plate therebetween.

Abstract: The present invention provides methods to control phase shift of delay demodulation devices to reduce Polarization Dependent wavelength (PD?) to be less than, for example, 0.5 GHz (i.e. 0.004 nm).

Abstract: Delay demodulation devices with optimized temperature and pressure distribution on a Planar Lightwave Circuit (PLC) are provided. The delay demodulation device 1 comprises: an input waveguide 2, which receives DQPSK signals; a Y-shape waveguide 3, which splits the light waveguide 2; a first Mach-Zehnder interferometer 4; and a second Mach-Zehnder interferometer 5. Both ends of arm waveguides 8, 9 on Mach-Zehnder interferometer 4 and the both ends of arm waveguides 12, 13 on Mach-Zehnder interferometer 5 are bent toward the center portion of the PLC. Because of the angle, the lengths of these arm waveguides 8, 9 are shortened in the Z-direction, and input couplers 6, 10 and output couplers 7, 11 of the Mach-Zehnder interferometers are shortened as well in the Z-direction. Therefore, the area covered by the Mach-Zehnder interferometers 4, 5 is reduced.

Abstract: A delay demodulation device, which reduces chip size and polarization dependent frequency (PDf), is provided. The delay demodulation device comprises: an input waveguide, which receives DQPSK signals; a Y-shape waveguide, which splits the input waveguide; a first Mach-Zehnder interferometer; and a second Mach-Zehnder interferometer. Both end of two arm waveguides of first Mach-Zehnder interferometer and both ends of two arm waveguides of second Mach-Zehnder interferometer are angled toward the center portion of a Planar Lightwave Circuit (PLC). Because of the angle, the length of the two arm waveguides of the first Mach-Zehnder interferometer and the length of the two arm waveguides of the second Mach-Zehnder interferometer in Z-direction can be shortened, and input couplers and output couplers of the Mach-Zehnder interferometers in Z-direction can be shortened as well. The area occupied by the Mach-Zehnder interferometers is also reduced.

Abstract: A delay-line demodulator for demodulating a differential quadrature phase shift keying (DQPSK) signal is provided. The demodulator includes two Mach-Zehnder interferometers individually comprising two waveguides having different lengths therebetween and through which a light signal branched from the DQPSK signal propagates, respectively. A phase of the light signal propagating at one of the waveguides is delayed as compared to a phase of the light signal propagating at another one of the waveguides, wherein a divergence amount of polarization is adjusted by driving sets of heaters that are facing each other and sandwiching a half wavelength plate therebetween.

Abstract: An optical integrated circuit 1 according to the present invention includes a planar lightwave circuit 2, and a semiconductor element 3, which are fixed at one contact surface 12. A semiconductor optical amplifier (SOA) 9 is formed on a semiconductor substrate 8. A semiconductor waveguide 10 and a semiconductor waveguide 11 are formed on an input side and an output side of SOA 9, respectively. The semiconductor waveguide 11 has a turnaround portion 11a turned around on the semiconductor substrate 8. Respective ends of the optical waveguides 5 and 6 on a PLC platform 4 and respective ends of semiconductor waveguides 10 and 11 are optically coupled with each other at the contact surface 12.

Abstract: An arrayed waveguide grating optical multiplexer/demultiplexer 10 of the present invention 10 comprises one arrayed waveguide grating (AWG) 20 having two input waveguides 21, 22 and two output waveguide-groups 23, 24, and a Mach Zehnder Interferometer-type interleaver 30 integrated with the AWG 20. Each of the input waveguides 21, 22 is formed by a Mach Zehnder Interferometer having the same free spectral range as the frequency spacing of the AWG. The Interferometer includes a 3 dB coupler 51 connected to the 3 dB coupler 32, a 100% coupler 52, a waveguide delay line 53 with an optical path length difference ?L of 4.1 mm formed between the couplers 51, 52, and a phase shifter 54 of ? formed between the 100% coupler 52 and a 3 dB coupler 55 connected to the first slab waveguide 25.

Abstract: An arrayed waveguide grating optical multiplexer/demultiplexer includes an arrayed waveguide grating formed on a substrate. The arrayed waveguide grating includes two slab waveguides, one arrayed waveguide, first input/output waveguides respectively connected to each end facet of slab waveguides, and second input/output waveguide-groups respectively connected to the end facets. The first input/output waveguides are provided for inputting or outputting a plurality of lights (?1˜?n) each of which has a different wavelength and multiplexed. The second input/output waveguides are provided for individually inputting or outputting a plurality of lights (?1˜?n). One arrayed waveguide 23 can be used to carry out simultaneously multiplexing and demultiplexing. It is able to carry out simultaneously multiplexing and demultiplexing with one arrayed waveguide grating.

Abstract: An arrayed waveguide grating has optical input waveguides, a first slab waveguide, an arrayed waveguide comprising plural waveguides of mutually-different lengths, a second slab waveguide and plural optical output waveguides. The first slab waveguide is divided along division surfaces crossing the light path into divided slab waveguides. The divided slab waveguide is temperature-dependently moved along the division surfaces by sliding members which are formed of members exhibiting different expansion/contraction corresponding to temperature change. The sliding members are configured to move the divided slab waveguide in their respective mutually-different temperature ranges in the operating temperature range of the arrayed waveguide grating. A sliding distance of the divided slab waveguide is used as a temperature-dependence reduction amount that varies as temperature changes so as to reduce the temperature difference of the light transmission center wavelength of the arrayed waveguide grating.