摘要:
An optical waveguide of the invention is formed by depositing an underclad (1b) on a silicon substrate (11), by forming thereon a core (2) having, for instance, an arrayed waveguide grating circuit, and by covering the core with an overclad (1a), and, without disposing a half wave plate, can suppress an influence of polarization dependency attenuation and deterioration due to moisture absorption. An arrayed waveguide grating circuit includes at least one input waveguide, a first slab waveguide, an arrayed waveguide made of a plurality of channel waveguides arranged side by side with lengths different by a predetermined amount from each other, a second slab waveguide, and an output waveguide. The clad and the core are made of silica-based glass. When the thermal expansion coefficient of the substrate is α s , that of the underclad α uc , and that of the overclad α oc , α oc is equal to or greater than (α s -2.0×10 -7 ) and equal to or smaller than (α s +2.0×10 -7 ), and (α oc -α uc ) is equal to or smaller than (21.5×10 -7 ).
摘要:
The present invention relates to an optical signal processing apparatus and optical signal processing method which enable generation, waveform shaping, waveform measurement, waveform recording, correlation processing, and the like of optical pulses of 1-10 ps. A basic construction of the optical signal processing apparatus includes an optical waveguide (9), (13), (22), (26), (33), (37), (41), (56), a first means (2), (10), (14), (25), (36), (42), (57) for equally distributing output light of the optical waveguide, an optical waveguide comprising an aggregate of optical waveguides changing in optical length by a constant interval, an arrayed waveguide (3), (11), (15), (24), (32), (43), (58) for dividing the output light, second means (4), (12), (16), (23), (34), (35), (59) for focusing optical output of the arrayed waveguide, and a mirror (110), (402), (2021), (2048), (2115) for receiving and reflecting incident light focused by the second means. Or, the apparatus includes an optical waveguide, first means for equally distributing output light of the optical waveguide, an arrayed waveguide comprising an aggregate of optical waveguides changing in optical length by a constant interval for dividing the output light, second means for focusing optical output of the arrayed waveguide, and a spatial filter (5), (17), (109) for receiving light focused by the second means to distribute the incident light on a straight line and making desired amplitude or phase modulation of the light according to the position on the straight line and reflecting the light.
摘要:
An optical waveguide with low polarization dependency is provided. The silica based optical waveguide comprises a substrate (1), a core waveguide (2) formed thereon, and an over cladding part (3b) comprising a silica based glass with a refractive index lowering dopant and a refractive index increasing dopant added, formed on the substrate so as to cover the core waveguide. The segregation layer (3a) with a higher concentration of the refractive index increasing dopant is formed in contact with the substrate and the core waveguide. The over cladding part (3) is provided by forming a porous silica based glass layer by accumulating glass fine particles and a dopant such as B 2 O 3 or P 2 O 5 on the substrate (1) by FHD method so as to cover the core waveguide (2), then, sintering the porous silica based glass layer for transmitting the light in the core.
摘要:
A wavelength selective polarization beam device uses waveguide grating routers (WGRs) having birefringent grating waveguides. When the device is used as a splitter it separates different wavelength channels of a wavelength division multiplexed (WDM) signal as well as the orthogonal polarization components of each wavelength channel. Since the WGR device is reciprocal, it can also be used as a combiner to combine the orthogonal polarization components of each wavelength channel into a WDM signal.
摘要:
A no polarization dependent waveguide type optical circuit can resolve polarization dependency completely and can reduce reflected return light. An intermediate portion of the two connecting waveguide (9), (10) are formed with S-shaped waveguides of the same shape consisted of respectively two curved waveguides (9B), (9E), (10B), (10E) or two curved waveguides and straight waveguides (9C), (9F), (10C), (10F) connecting the curved waveguides. One or two polarization mode converters are provided in a groove (11) formed across the S-shaped waveguide, and a perpendicular line to an incident surface of light of the polarization mode converter (12) and the S-shaped waveguide forms an angle greater than 0° .
摘要:
The essential feature is the step of generating a controllable 'dynamic' intensity field profile with a controllable beating pattern in a multimode superposition of different modes, as e.g., a fundamental mode and a higher order mode as e,g., the TE0 mode and TE1 mode of an input wavelength entering the input site of an AWG apparatus, whereby said beating pattern is controlled in a fixed, or in variable, predetermined way, as e.g., with a fixed or a wavelength dependent power ratio and beating pattern, for improving the mode overlap in a receiver waveguide associated with an output site of said apparatus. With variable conditions, a lower number of converter units is required. In a 8:1 multiplexer, for example, there is needed just one converter unit at its output. A 1:8 demultiplexer can be obtained by solely reversing the AWG apparatus.
摘要:
An optical device having an array of substantially equal-length optical waveguides. Each one of the optical waveguides includes one or more straight segments, one or more curved segments, and optionally, one or more transition segments. According to my invention, the sum of the lengths of the straight segments in each of the waveguides is substantially equal. Similarly, the sum of the lengths of the curved segments in each of the waveguides may be substantially equal as well. Finally, the sum of the lengths of optional transition segments in each of the waveguides may also be substantially equal. Advantageously, my device exhibits relative lengths that are robust to fabrication errors and have low polarization sensitivity.
摘要:
A wavelength division multi/demultiplexer multi/demultiplexes incident light to emit demultiplexed lights from each of a plurality of light output ends and includes a first wavelength division multi/demultiplexing circuit (19) having at least one light input end (2) and a plurality of light output end (6); and second wavelength division multi/demultiplexing circuits (20) of AWG type formed on a substrate, including a plurality of light input and output ends (2,6), one or two light multiplexing and demultiplexing sections (3,5), and a plurality of arrayed waveguides (4), and having a transmission bandwidth different from that of the first circuit, the transmission bandwidth indicating the width of a light frequency that can pass through each light input and output end, wherein the first circuit and at least one of the second circuits are optically connected together (21), and wherein the light output ends of the final second circuit are used as the light output ends of the wavelength division multi/demultiplexer. It is possible to greatly increase the number of channels of the wavelength division multi/demultiplexer using the AWG type wavelength division multi/demultiplexing circuit.