摘要:
A broad-band light source using a semiconductor optical amplifier is provided. The broad-band light source includes the semiconductor optical amplifier including an active layer serving as a gain area, an under-cladding layer, an over-cladding layer, and antireflection layers formed at both ends of the active layer; and a reflector, located at the outside of the semiconductor optical amplifier, for reflecting light outputted from the semiconductor optical amplifier so that the reflected light is inputted back to the active layer so as to minimize gain ripple of the semiconductor optical amplifier.
摘要:
A reflective semiconductor optical amplifier light source is disclosed. The reflective semiconductor optical amplifier light source includes a transmissive type semiconductor optical amplifier for creating and amplifying spontaneous emission light, a reflector for reflecting amplified spontaneous emission light outputted from the semiconductor optical amplifier such that amplified spontaneous emission light is reflected back into the semiconductor optical amplifier, and a bandpass filter having a predetermined wavelength band width for limiting wavelength bands of the amplified spontaneous emission light capable of passing through the bandpass filter. In one aspect of the invention, the bandpass filter is interposed between the semiconductor optical amplifier and the reflector. In another aspect, a polarization filter is imposed to limit the reflected emission light to a predetermined polarization.
摘要:
A SCM-PON using WDM includes: an OLT for transferring downstream data from an external service provider through downstream optical signals and transferring upstream data transferred through upstream optical signals to an outside; an ODN for distributing the downstream optical signals from the OLT and multiplexing the upstream optical signals to the OLT; and a plurality of ONUs for processing the downstream optical signals transferred from the OLT through the ODN and transferring upstream data of subscribers for the OLT through the upstream optical signals, wherein the optical signals between the OLT and the ONUs are divided into wavelength channels with different wavelengths and sub-carrier channels obtained by time-dividing the wavelength channels, and the upstream data and the downstream data are transferred through the sub-carrier channels.
摘要:
Disclosed are optical signal transmission apparatus including a reflective gain-clamped semiconductor optical amplifier and optical communication system using the optical signal transmission apparatus, which can improve modulation speed and optical power by effectively suppressing intensity noise of an incoherent light source. The optical signal transmission apparatus comprises a light source; a reflective gain-clamped semiconductor optical amplifier to generate gain-clamped optical signals having a substantially constant output intensity in a gain saturation region; a wavelength division multiplexing apparatus configured to spectrum-slice light from the light source, provide the spectrum-sliced light to the reflective gain-clamped semiconductor optical amplifier, and multiplex optical signals gain-clamped by the reflective gain-clamped optical amplifier, and a circulator for inputting the light generated by the light source to the wavelength division multiplexing apparatus, and outputting the optical signal multiplexed by the wavelength division multiplexing apparatus to a transmission link.
摘要:
An optical transmitter module for creating an optical signal having the same wavelength as an incoherent light inputted thereinto is provided. The module includes a substrate, a multi-layer crystal growth layer including a first area for amplifying the incoherent light and the optical signal and a second area for creating an optical signal having the same wavelength as the incoherent light amplified by means of the first area, and an electrode unit for independently injecting currents into the areas of the multi-layer crystal growth layer. A light generated at a broadband light source is spectrum-sliced and injected into the optical transmitter module so that a wavelength division multiplexing light source is realised.
摘要:
A broadband light source includes an optical amplifier having amplifying mediums connected in series outputs an amplified spontaneous emission light over a wide wavelength range forward or backward. A circulator connected in series to the optical amplifier returns back to the amplifier spontaneous emission light outputted backwardly from the amplifier. A first pumping means located between the circulator and the optical amplifier pumps a pumping light to the optical amplifier, and a second pumping means located after the optical amplifier pumps a pumping light to the optical amplifier.
摘要:
Disclosed is a wavelength-division multiplexing-passive optical network having a central office including a plurality of first working and protection transmit/receive modules, working and protection optical transmitters, and a plurality of first optical switches, the first working and protection transmit/receive modules generating downstream optical signals and detecting upstream optical signals having corresponding wavelengths, the working and protection optical transmitters generating broadcasting optical signals, the first optical switches performing a switching operation when faults occur, a plurality of subscriber units for receiving broadcasting optical signals and downstream optical signals having corresponding wavelengths and generating upstream optical signals, the subscriber units including second optical switches, a remote node including working and protection optical splitters for dividing intensity of the broadcasting optical signals, the remote node being positioned between the subscriber units and the central office, working and protection main optical fibers for linking the central office with the remote node; and a plurality of working and protection branch optical fibers for linking the remote node with the subscriber units, respectively.
摘要:
An optical fiber amplifier features an optical amplifying section for amplifying an inputted optical signal. A sampling section is provided for shunting part of the optical signal amplified by the optical amplifying section and detecting a first test light belonging to a short wavelength band and a second test light belonging to a long wavelength band. An input power control circuit serves to compare respective powers of the first and second test lights and then outputs a control signal for controlling an input power of the optical signal inputted to the optical amplifying section according to the power differential of the first and second test lights. An output power control circuit derives an output power of the optical amplifying section from the power of the optical signal shunted at the sampling section and also controls the optical amplifying section so that the output power of the optical amplifying section attains a predetermined value. A variable attenuator controls the power of the optical signal inputted to the optical amplifying section according to the control signal.
摘要:
A reflective semiconductor optical amplifier includes a substrate, a waveguide with a buried heterostructure formed by sequentially laminating a lower cladding, an active layer, and an upper cladding on the substrate, the waveguide including, sequentially, respective straight line, curved and tapered waveguide regions. A current blocking layer surrounds the waveguide to prevent electric current from flowing outside the active layer. Selectively etching portions of the current blocking layer and the substrate around the waveguide forms a trench to reduce parasitic capacitance. Further features include a window region on one end of the tapered waveguide region, an anti-reflection surface on one end of the window region, and a high-reflection surface on one end of the straight line waveguide region.
摘要:
The wideband optical fiber optical includes a circulator. In addition the amplifier outputs the amplified spontaneous emission (ASE) and the S-band optical signals. At least one optical fiber grating is used for passing the C- and L-band optical signals. A wavelength selective splitter outputs the L-band optical signal. A first optical fiber amplifying unit connected with the optical fiber grating and the first port of the wavelength selective splitter, for amplifying the C- and L-band optical signals and for outputting the ASE to the optical fiber grating. A second optical fiber amplifying unit for amplifying the L-band optical signals inputted from the second port of the wavelength selective splitter and for outputting the amplified L-band optical signals to the third terminal of the outputting unit. A third optical fiber amplifying unit amplifies the S-band optical signals input from the third port of the circulator, and outputs the amplified S-band optical signals to the first terminal of the outputting unit.