Abstract: Optical apparatus for combining and splitting optical signals using folded waveguides and method for making the same are disclosed. According to one aspect of the present invention, at least one waveguide used in the optical apparatus is folded around according to a predefined curve to couple to other waveguides. The predefined curve is so designed as to minimize possible insertion loss as a result of such folding of the waveguide. The proper folding of the waveguide leads to modified designs of the optical devices with all the ports on one side so as to simplify the alignment procedures afterward. In addition, the optical device according to the present invention has much smaller footprint and makes it possible to increase higher yield from fabricating substrate material on which the waveguides are formed.

Abstract: Techniques for designing, configuring or manufacturing polarization maintaining couplers (e.g. fiber arrays or splitters) are disclosed. According to one embodiment, a pair of polarization maintaining couplers are designed by a method including forming V-shaped troughs in two platforms (e.g. silicon based); placing two fibers respectively in the troughs so that both of the platforms can be closed up as a whole part; and obtaining the pair of the polarization maintaining couplers by a precision cut of the whole part somewhere in the middle thereof.

Abstract: An optical multi-channel data communication link transmits data from a transmitter to a remote receiver. The link includes a multimode laser diode source connected to the transmitter, a device for modulating the source with each channel of data to generate a modulated light wave, and a wavelength division multiplexing device at the transmitter. The wavelength division multiplexing device has paraxial optics for multiplexing the light waves to produce a multiplexed signal. Multimode fiber optic means are connected to the multiplexer and pass the multiplexed signal to the remote receiver. A wavelength division multiplexer has paraxial optics for demultiplexing the multiplexed signals at the receiver to produce demultiplexed light waves. Each of the demultiplexed light waves are converted for use by the receiver.

Abstract: A multiwavelength sensor for sensing light scattered from a scattering medium includes a light source, a uniform broadband reflection grating at the Littrow position, a fiber, and a detector. Light from the source is incident on the grating, which diffracts the light. The fiber has a first end into which the light diffracted from the grating is received and has a second end from which the light exits, the fiber being positioned so that the light is incident upon and scattered from the scattering medium. At least some of the light scattered from the medium is scattered back into the second end and out of the first end and incident upon the diffraction grating. Light out of the first end and diffracted from the grating is incident on the detector. The system is fully transparent so that light traveling toward the second end and light traveling back toward the first end are optically isolated and cross-talk is substantially nonexistent.