Nonlinear analysis method and device for photoelectric detector

Abstract

The invention relates to a photoelectric detector nonlinear analysis method and device, and belongs to the technical field of photoelectric device measurement. By changing the power of a coherent three-wavelength optical signal and a direct current optical signal, the power change condition of direct current, fundamental frequency and intermodulation components corresponding to an electric signal output by a photoelectric detector is analyzed; the non-linear parameters of the photoelectric detector under different input optical powers can be obtained, the relative frequency difference among the coherent three-wavelength optical signals is changed by using the frequency control unit, the non-linear parameters of the photoelectric detector under different frequencies can be analyzed, and the device is simple in structure, large in dynamic range and high in reliability. Extraction of various nonlinear parameters such as 1dB compression current, second-order cross modulation and third-order cross modulation of the photoelectric detector can be achieved, and the method can be widely applied to the fields of optical communication, laser radar, quantum communication, microwave photons, optical fiber sensing and the like.

Description

technical field [0001] The invention belongs to the technical field of photoelectric device measurement, and more specifically relates to a photoelectric detector nonlinear analysis method and device. Background technique [0002] Microwave photonic technology combines microwave and light, which has the advantages of large bandwidth, anti-electromagnetic interference, and low loss. It has important applications in broadband wireless access networks, high-precision sensor networks, quantum communications, and optoelectronic weapons and equipment. The main working indicators for evaluating the performance of microwave photonic links are noise figure, gain, and spurious-free dynamic range, and these indicators are closely related to the nonlinearity of the link. [0003] As an important device in the microwave photonic link, the photodetector's linear performance largely determines the performance of the microwave photonic link. Usually, the 1dB compression current and the thir...

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Problems solved by technology

The laser beat frequency method "Measurement of IP3 in p-i-n Photodetectors and Proposed Performance Requirements for RF Fiber-OpticLinks" uses two sets of four laser beat frequencies to generate two different test signals, which will not introduce the nonlinearity of the signal source, but the laser The stability is difficult to control, resulting in the frequency of the beat frequency signal is not stable enough; the dual signal source direct modulation method controls the modulator at the linear point, theoretically only odd harmonics are generated, but the bias point of the modulator is difficult to control, and its drift The generated second harmonic and the fundamental frequency of another signal will generate a third-order intermodulation signal in the photodetector, making it impossible to distinguish whether the third-order intermodulation signal is generated by the nonlinearity of the photodetector or the modulator《The Frequency Behavior of the Third-Order Intercept Point in a Waveguide Photodiode"; the direct modulation method of three signal sources "Three-Tone Characterization of High-Linearity Waveguide Uni-Traveling-Carrier Photodiodes" uses three signal sources to modulate three beams of optical carriers respectively, which can be used in the frequency domain The third-order intermodulation points generated by the modulator and photodetector are distinguished to remove the nonlinear influence of the modulator, but in this method, the signal entering the photodetector is not an ideal two-tone signal, and a 4 lasers, the system is more complex

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