1260 results about "Optical circulator" patented technology

Diffraction grating based fiber optic interferometric systems for use in optical coherence tomography, wherein sample and reference light beams are formed by a first beam splitter and the sample light beam received from a sample and a reference light beam are combined on a second beam splitter. In one embodiment, the first beam splitter is an approximately 50 / 50 beam splitter, and the second beam splitter is a non 50 / 50 beam splitter. More than half of the energy of the sample light beam is directed into the combined beam and less than half of the energy of the reference light beam are directed into the combined beam by the second beam splitter. In another embodiment, the first beam splitter is a non 50 / 50 beam splitter and the second beam splitter is an approximately 50 / 50 beam splitter. An optical circulator is provided to enable the sample light beam to bypass the first beam splitter after interaction with a sample. Two combined beams are formed by the second beam splitter for detection by two respective detectors. More than half of the energy of the light source provided to the first beam splitter is directed into the sample light beam and less than half of the energy is directed into the reference light beam. The energy distribution between the sample and reference light beams can be controlled by selection of the characteristics of the beam splitters.

Disclosed is a remote antenna unit and a wavelength division multiplexing network. The remote antenna unit includes: an optical circulator having a plurality of ports; an electric field absorption modulator having a first input / output end and a second reflective end, the electric field absorption modulator configured to demodulate an optical signal into a first data signal, and modulate the demodulated optical signal according to a second electric data signal; and a filter disposed between the optical circulator and the electric field absorption modulator, for the filter configured to transmit an optical signal having a particular wavelength from among optical signals input from a port of the optical circulator toward the electric field absorption modulator and reflecting the remaining optical signals into the port of the optical circulator, and inputting the optical signal from the electric field absorption modulator into the port of the optical circulator.

A tunable pulsed laser source includes a seed source adapted to generate a seed signal and an optical circulator having a first port coupled to the seed source, a second port, and a third port. The tunable pulsed laser source also includes a modulator driver adapted to produce a shaped electrical waveform and an amplitude modulator coupled to the modulator driver and adapted to receive the shaped electrical waveform. The amplitude modulator is characterized by a first side coupled to the second port of the optical circulator and a second side. The tunable pulsed laser source further includes a first optical amplifier characterized by an input end and a reflective end. The input end is coupled to the second side of the amplitude modulator. Moreover, the tunable pulsed laser source includes a second optical amplifier coupled to the third port of the optical circulator.

A wavelength selective switch of the invention separates WDM light coming out from an input fiber of a fiber collimator array according to its wavelength, in a diffraction grating, and reflects each wavelength channel proceeding in different directions by MEMS mirrors corresponding to a mirror array. In the MEMS mirrors, the angles of their reflecting surfaces are set corresponding to the location of the output port which is set in the output address of the wavelength channel to be injected. For each of the wavelength channels that reach the target output port, one part of each is reflected by the end face of an output fiber, and the reflected light is returned to the input port, and sent to a channel monitor via an optical circulator, so that the optical power corresponding to each wavelength channel is monitored. As a result it is possible to provide a small size, and low-cost, wavelength selective switch, that can monitor the power of each wavelength channel guided to a plurality of output ports, with good accuracy.