31 results about "Degenerate four wave mixing" patented technology

A system, method, and apparatus for delayed optical router based on slow light and nondegenerate four-wave mixing processes are presented, in which three laser pulses interact with a three-level nonlinear optical medium composing two closely spaced ground states and an excited state. The delayed optical routing mechanism is based on a slow light phenomenon, in which a group velocity of an incoming input signal pulse is slowed down due to quantum coherence induced refractive index change. The two-photon coherence induced on the ground states via electromagnetically induced transparency is optically recovered via nondegenerate four-wave mixing processes. The nondegenerate four-wave mixing generation is enhanced owing to absorption cancellation. In this case, the individual pulse switching / routing time is limited by the coherence decay time that is much faster than population decay time, where the population decay-time is a limiting factor of conventional switching devices. In the present invention of the delayed optical router the overall switching / routing time, however, is controlled to be delayed by using the slow light. Even though the overall switching / routing time can be delayed, the switching bandwidth of the present invention is not degraded at all because the input and output signal's group velocity across the delayed optical router is still same. Therefore, the present invention of the delayed optical router gives an advantage of wide-bandwidth optical data traffic control using a narrow-bandwidth processing unit such as an electronic device. Another advantage is signal amplifications owing to the dark-resonance enhanced nondegenerate four-wave mixing processes.

A system, method, and apparatus for delayed optical logic gates based on slow light and enhanced nondegenerate four-wave mixing processes, where a single or multiple delayed optical routers are utilized for dark resonance interactions in which two-color lasers interact with a three-level nonlinear optical medium comprised of two ground states and one excited state through the nondegenerate four-wave mixing processes. The delayed optical logic mechanism is based on combination of single or multiple dark resonance-induced two-photon coherence conversion via slow light phenomenon. The two-photon coherence induced on the ground states is optically detected via nondegenerate four-wave mixing processes. The nondegenerate four-wave mixing generation is enhanced owing to dark resonance or electromagnetically induced transparency. The gating time and bandwidth of the present delayed optical logic gates is invariant to the delayed time of the delayed optical router because IN and OUT bandwidth across the nonlinear medium must be same. The present invention of delayed optical logic gates have potential to keep up ultra-high-bandwidth optical information processing using relatively slow electronic processing devices.

The invention provides a method for achieving all-optical quantum random number generation through the four-wave mixing effect. Two beams of pulse light with different wavelengths and continuous light pass through a highly nonlinear optical fiber, generate the degenerate four-wave mixing effect in the highly nonlinear optical fiber, and generate signal light with the phase having quantum randomness. The generated signal light is divided into two paths with equal intensity, one path of light interferes with the other path of light after delay, the intensity of output signals randomly occurs in the '0' state and in the '1' state, and accordingly quantization-free all-optical high-speed quantum random codes are obtained in real time. Devices used in the method include a mode-locked pulse laser device, a narrow-line-width laser device, the highly nonlinear optical fiber, a filter, a light delay line and an optical fiber coupler. The center wavelength of the mode-locked pulse laser device is not equal to that of the narrow-line-width laser device. The method for generating random numbers is conducted completely in an optical domain, can break through the electronic bottleneck limitation, does not need the light quantization technology, and is capable of generating the all-optical high-speed quantum random codes in real time.

The invention discloses a DFWM (Degenerate Four-Wave Mixing) spectroscopic technology based method for determining the date of cultural relics, which comprises the following steps of: dividing a laser beam by a beam splitting device into three beams to be incident into a sample to be determined; receiving a generated DFWM signal by a photoelectric detector; measuring the intensity of the DFWM signal to judge the content information of 14C; and reckoning the date of the cultural relics based on the decay theory of the 14C according to the content information of the 14C. The invention has the advantages of simple device, easy and feasible operation, and capability of eliminating Doppler widening and can overcome the deficiencies of poor dating precision, high sampling amount, complicated device, high operation difficulty, high cost and the like in the traditional isotope-dating technology.

The invention relates to an optical parametric oscillator, which comprises a nonlinear optical material (1) with the double-zero dispersion wavelength, a high reflector (2), an output mirror (3), a parametric oscillation optical beam collimator (4), a parametric optical line width compressor (5), a pumped optical coupler (6), a lambda / 2 phase retarder (7), a laser power controller (8) and an optical isolator (9). The nonlinear optical material (1) has a double-zero dispersion wavelength and is arranged in a resonant cavity formed by the high reflector and the output mirror. The pumped opticalwavelength is in the anomalous dispersion regime of the photonic crystal fiber, thereby ensuring the phase matching conditions and generating the highly efficient four-wave mixing effect. For the parametric oscillation formed by simplifying the four-wave mixing, the wavelengths of the two parametric lights are respectively arranged at the double-zero dispersion wavelength of the photonic crystal optical fiber, thereby realizing the group velocity dispersion compensation of the parametric light, solving the problem of the ultra-short pulse dispersion compensation, and greatly reducing the pumping threshold.

The invention relates to a tunable ultra-fast dark pulse generation device and method, aiming to solve the problems faced by the traditional dark pulse generation system that the rate is limited by the length of the physical cavity and difficult to tune, the system is large in size, and the operation process is complicated. The device includes a pump unit, a modulation unit, an integrated microcavity unit, a monitoring unit, and an analysis unit; the method includes adjusting the power and wavelength of the narrow-linewidth pump laser emitted by the pump unit, electro-optical modulation of the pump laser through the modulation unit, and integration The microcavity unit receives the narrow-linewidth pump laser modulated by the modulation unit, and the non-degenerate four-wave mixing effect occurs in the cavity to realize frequency expansion, forming a dark pulse and using the analysis unit to measure and analyze the time-domain waveform of the dark pulse. The process of analysis. The invention promotes the development of ultra-fast dark pulse technology and practical applications, and has important research significance and application prospects.