Abstract: An apparatus for adjusting the channel width of a multi-channel fiber amplifier light source, including an erbium-doped optical fiber amplifier constructed to generate a spontaneously emitted, amplified noise beam under a condition that no optical signal is applied thereto, the amplifier being used as a light source for wavelength division multiplexing, namely, a fiber amplifier light source. By the angle-turned Fabry-Perot etalon filter and the fiber-optic beam expander, the channel width can be easily controlled without affecting the free spectral range and the power of output light.

Abstract: A frame phase aligner for a transfer system includes selection circuitry for selecting one of a plurality of input signal groups, which include data, a clock signal, an inverse clock signal and a frame synchronous signal, received from outside of the frame phase aligner. A selection signal generator provides the selection circuitry with a selection signal according to write data input from outside of the frame phase aligner, so that the selection circuitry selects one of the plurality of input signal groups according to the selection signal indicative of the setup environment of the transfer system. A control signal generator generates control clock signals and a retiming control signal in order to demultiplex selected data of the input signal group selected. A demultiplexer demultiplexes data selected to form parallel data, retimes the parallel data, and controls the phase of the parallel data according to the control retiming signal and the control clock signals output from the control signal generator.