76results about How to "Great modulation depth" patented technology

Polarization effects are managed to provide differential timing information for localizing disturbances affecting two or more counter-propagating light signals on one or more optical waveguides passing through a detection zone. Activity can be localized to a point for a security perimeter. Events causing optical disturbance can be mapped to points along a straight line, a perimeter or arbitrary pattern or an array. Events cause local changes in optical properties in the optical waveguide, in particular an optical fiber. Short term local changes are distinguishable from phase changes of light travel in the waveguide by managing the polarization state of input and output beams.

The invention provides a terahertz modulator based on low-dimension electron plasma waves, a manufacturing method thereof and a high-speed modulation method. The terahertz modulator comprises a plasmon and a resonant cavity. The resonance absorption mechanism is caused by electronic collective oscillation (plasma waves, namely Plasmon). In order to increase the coupling strength of the plasma waves and the plasmon, a GaN / AlGaN high-electronic-mobility transistor structure with a raster grid is integrated in a terahertz Fabry-Perot resonant cavity, plasmon polariton is formed through strong coupling of the plasmon and the resonant cavity mode. By means of the strong coupling effect, the transmission coefficient of the resonant cavity mode is the maximum at the resonance point, resonance conditions of the plasmon and the resonant cavity mode are adjusted and controlled by changing the raster pressure, and efficient and high-speed modulation for terahertz waves is achieved. The working principle and the achieving technology of the device are introduced in detail, and a good solution is provided for relevant applications.

The invention relates to an airborne wind speed measurement laser radar system. The system comprises a narrow-linewidth laser pulse light source module, a radar transceiving optical antenna module and a signal receiving and processing module. The narrow-linewidth laser pulse light source module comprises a narrow-linewidth seed light source, an optical fiber preamplifier, an acousto-optic modulator, a C-waveband boosting semiconductor optical amplifier and an optical fiber main amplifier. The radar transceiving optical antenna module is connected with the narrow-linewidth laser pulse light source module and comprises an optical fiber circulator, an optical switch and an optical antenna. The signal receiving and processing module is connected with the narrow-linewidth laser pulse light source module and the radar transceiving optical antenna module; the signal receiving and processing module comprises an optical fiber adjustable attenuator, an optical fiber beam combiner, a balance photoelectric detector, a signal processing circuit and an embedded computer. The airborne wind speed measurement laser radar system is reasonable in structural design and stable and reliable in use, can provide real-time wind speed data for an airborne atmospheric data computer, improves the performance of an airplane, and guarantees the flight safety.