Real-time vector analysis method and device for detecting optical signal with bandwidth greater than 1 THz

A real-time vector analysis device for detecting an optical signal with a bandwidth greater than 1 THz, comprising:

• a time-lens focusing system, a first optical fiber mode-locked laser, an optical band-pass filter, a first dispersion compensation optical fiber, a first polarization controller, a second polarization controller, a coherent receiver, and a real-time oscilloscope, wherein,
• the time-lens focusing system is configured for performing a temporal Fourier transform on a signal under test to realize a mapping transformation from a frequency domain to a time domain of the signal under test;
• the first optical fiber mode-locked laser is configured for producing an ultrashort pulse source sequence with a pulse width less than 1 ps and a pulse repetition rate with an order of MHz;
• the first dispersion compensation optical fiber is configured for using in the first optical fiber mode-locked laser to function a dispersion stretching to realize a chirped frequency swept-source;
• the optical band-pass filter is configured for controlling a working spectral range of the first optical fiber mode-locked laser, to avoid an aliasing of adjacent pulses during a time-stretching process;
• the first polarization controller and second polarization controller are configured respectively to control a polarization state of a signal and a polarization state of a local oscillator source inputted to the coherent receiver, so that a strongest interference effect of the signal light and the local oscillator source is achieved;
• the coherent receiver is configured to realize the coherent detection of the signal light and the local oscillator, and convert an optical signal into an electrical signal for output;
• and
• the real-time oscilloscope is configured for sampling and performing an analog-to-digital convert on the electrical signal outputted by the coherent receiver and displaying the electrical signal in real time;
• wherein the time-lens focusing system comprises an electro-optic intensity modulator, an electro-optic phase modulator, an arbitrary waveform generator, a second dispersion compensation optical fiber, and a first optical amplifier, wherein,
• the electro-optic intensity modulator is configured for implementing a time window interception on the signal under test;
• the electro-optic phase modulator is configured for loading a temporal quadratic phase on an optical signal within the time window;
• the arbitrary waveform generator is configured for producing a radio frequency signal applied on the electro-optic intensity modulator and the electro-optic phase modulator;
• the first optical amplifier is configured for amplifying the optical signal outputted by the electro-optic intensity modulator to compensate an optical power loss caused by an electro-optic intensity modulation and a system link;
• and
• the second dispersion compensation optical fiber is configured for performing a dispersion compression on the optical signal after being quadratic phase modulated to obtain a spectral information of time domain of the signal under test.