Abstract: An unidirectional short-wave infrared fiber laser, comprising a theta cavity, with a gain unit based on rare-earth cations-doped fiber, the theta cavity having a ring cavity with two additional 2 input ports×2 output ports directional couplers DC1 and DC2 inserted therein, one port of the directional coupler DC1 connected to another port of the directional coupler DC2, forming an S-shaped feedback; a band-pass filter to select at a laser wavelength by filtering through transmission inside the theta cavity, the band-pass filter is one of the list comprising a grating-based filter, a Fabry-Perot etalon, and a phase shifted fiber-Bragg grating; and a reflective fiber Bragg grating (FBG) to select the laser wavelength by filtering through reflection inside the theta cavity, the Bragg grating is a notch filter, and the fiber Bragg grating (FBG) is attached to an unused port of the directional coupler DC1 or DC2.

Abstract: System and methods for producing a plurality of Sinc shaped pulses in the time domain include a light source for providing an input light signal having an input frequency, and at least one spectrum shaper for producing the plurality of Sinc shaped pulses from the input light signal. The spectrum shaper may include an amplitude modulator, at least one radio-frequency generator and a bias voltage generator.

Abstract: System and methods for producing a plurality of Sinc shaped pulses in the time domain include a light source for providing an input light signal having an input frequency, and at least one spectrum shaper for producing the plurality of Sinc shaped pulses from the input light signal. The spectrum shaper may include an amplitude modulator, at least one radio-frequency generator and a bias voltage generator.

Abstract: An optical domain spectrum analyzer/channelizer employs multicasting of an analog signal onto a wavelength division multiplexing grid, followed by spectral slicing using a periodic optical domain filter. This technique allows for a large number of high resolution channels. Wideband, 100% duty cycle, spectrum analysis or channelization is made possible permitting continuous time wideband spectral monitoring. The instantaneous bandwidth of the spectrum analyzer/channelizer is equal to the full radio frequency bandwidth of the analyzer/channelizer.