Showing papers on "Wavelength-division multiplexing published in 1977"

Wavelength multiplexing in multimode optical fibers.

Abstract: The capacity of optical fiber transmission systems could be increased by multiplexing several signals at different wavelengths on each fiber. This paper considers various multiplex system designs that might be used with multimode fiber transmission systems. In each case, the required multiplexer size and material properties are calculated as functions of the basic parameters of the fiber system. For fiber systems of the type currently being tested, a compact (~2 mm in diameter × 1 cm long), rugged, three-channel multiplexer could be constructed using a blazed plane reflection grating and graded-refractive-index (GRIN) optics; and it appears that such devices could be produced using available materials and technology. Multiplexers using thick gratings or multilayer dielectric filters are larger, more complicated, and require materials at the very edge of available technology. Multiplexers using a multiple thick grating or hologram could be even smaller than the blazed-grating devices, but materials having the required characteristics have not been demonstrated.

High-speed digital-signal transmission experiments by optical wavelength-division multiplexing

Abstract: The letter reports results obtained with laboratory transmission experiments on high-speed digital signals by optical wavelength-division multiplexing, using a newly developed optical multiplexer and demultiplexer, as well as other high-performance optical devices and fibres.

Full duplex transmission link over single-strand optical fiber.

Abstract: Full duplex transmission of television signals over a single optical fiber is demonstrated The transmission link uses directional couplers that possess high directivity and low insertion loss

Review of fiber optical communications

Abstract: This paper will discuss recent advances in optical fiber, fiber cabling, and light source technology. These advances will make it possible for widespread applications of fiber optical communications in the very near future. Developments in fiber waveguide have made possible the long distance transmission of high data rate information over a single fiber waveguide. Of the various fiber types, four are currently receiving the most attention because of their attenuation, dispersion, and cost characteristics. Semiconductor injection lasers have been developed that have lifetimes exceeding 10,000 hours with projected lifetimes extending beyond 100,000 hours. Receiver technology is well developed and avalanche photodiodes provide high sensitivity receiver performance for most data bandwidths of interest.

Laser Diodes for Fiber Communications

Abstract: Major areas of current research and development of laser diodes for fiber communications includes reliability studies of the "standard" CW AlGaAs lasers emitting at ~ 0.85 μm and advances in the technology of devices emitting in the 1 μm spectral region. Other areas of continuing research involve the control of lateral modes and the elimination of nonlinearities (kinks) in the power emission vs. current curves.

Optical multiplexer for multimode fiber transmission systems

Abstract: We have constructed and tested an optical multiplexer for use with multimode optical fibers. The device utilized a blazed plane reflection grating with a single GRIN‐rod lens, and was made from commercially available components. The wavelength spacing of the two channels was 27 nm, the insertion losses were ⩽2.4 dB, and the crosstalk was <−30 dB. Optimized versions of the device should be capable of providing at least four channels, with still lower insertion losses, in a rugged stable package 1–2 cm long by 2–4 mm in diameter.