摘要:
A single-fiber subassembly includes a first photodiode (2) for receiving incident light (21) and a laser diode (3) for transmitting emergent light (31), and a same-wavelength optical splitter (1) that has a positive direction. The same-wavelength optical splitter (1) includes a first birefringent plate (11), a half-wave plate (12), a 45° Faraday rotator (13), and a second birefringent plate (14) that is the same as the first birefringent plate (11), which are arranged in sequence along the positive direction and vertical to the positive direction. An included angle between an optical axis of the first birefringent plate (11) and the positive direction is α, where 0°
摘要:
Optical devices are disclosed consisting of optical chips (planar lightwave circuits) which have optically symmetric or matching designs and properties and optical components which create asymmetry in the optical devices. The devices find application in detection in coherent and non-coherent optical communications systems.
摘要:
An optical multiplexer/demultiplexer having a high isolation characteristic, a small polarization dependency and capable of being reduced in size is disclosed. An end portion of a core (15) and an end portion of a core (16) are arranged in opposed relation to each other with a thin-film filter (19) interposed therebetween. The end portion of the core (15) far from the filter and the end portion of the core (16) far from the filter are arranged in substantially parallel to each other. The core (17) is arranged in such a manner as to branch from the filter-side end portion of the core (15) and to be optically coupled with the core (15). The end portion of the core (15) near to the filter and the end portion of the core (16) near to the filter are curved. The end portion of the core (15) near to the filter is curved towards the core (17). The end portion of each of the core (15) and the core (16) far from the filter reaches an end of an optical waveguide substrate, and the end portion of the core (17) far from the filter reaches a side of the optical waveguide substrate.
摘要:
By judicious engineering of grating parameters such as tooth shape, duty cycle and phase offset, the grating strengths and effective indices of the polarization modes of a grated waveguide are adjusted over a wide range of values to achieve a desired level of polarization sensitivity, or insensitivity. In the typical example, the physical geometry of the grating teeth is adjusted so that degenerate behavior (nTE = nTM and KTE = KTM) is obtained for two polarization modes; the effective refractive indices and grating strengths are matched for the TE and TM polarization modes. In the current embodiment the sidewall gratings are used in which the tooth profile is selected in order to equalize the grating strength for each polarization mode.
摘要:
An optical waveguide device includes an LiNbO 3 substrate (26) and an optical waveguide (28) disposed on the LiNbO 3 substrate (26) by diffusing Ti therein. The LiNbO 3 substrate (26) has a step (80) on a surface thereof which corresponds to the area in which Ti is diffused. The step (80) has opposite side edges (80a) and a central area (80b) therebetween, the side edges (80b) having a height (Ts) greater than a height (Tc) of the central area (80b), whereby the side edges (80b) are raised higher than the central area (80b). The optical waveguide device has a relatively small coupling loss with respect to an optical fiber having a small light beam mode shape, thus eliminating optical device loss faults.
摘要:
An apparatus comprising a planar optical structure that includes an input coupler, first and second planar waveguides and an output coupler, all on a planar substrate. The input coupler is configured to divide an incoming light into two input light beams. Each of the first and second waveguides is configured to receive one of the two input light beams. The first waveguide has a first core with a width that is greater than a width of a second core of the second waveguide. At least one of the first or second planar waveguides is birefringent. The output coupler is configured to receive the light beams after passage through the first and second waveguides. A first output light beam from the output coupler is substantially TE polarized light and a second output light beam from the output coupler is substantially TM polarized light.