Approximation-free and iteration-free method for spectral analysis of intracavity electro-optic modulation type optical frequency comb, device and medium

A method comprising:

• step 1:
• calculating a residual phase delay of a single propagation of laser in a resonant cavity according to an incident laser frequency of a light source of an intracavity electro-optic modulation type optical frequency comb, a resonant frequency of the resonant cavity, an intracavity electro-optic modulation frequency, and intracavity material dispersion;
• step 2:
• performing an analysis of outgoing transmission characteristics of the light source, and obtaining corresponding outgoing laser electric field intensities En according to cyclic propagation times n in the resonant cavity;
• step 3:
• accumulating the outgoing laser electric field intensities En corresponding to all the cyclic propagation times n to obtain a complete outgoing laser electric field intensity E;
• step 4:
• using a Jacobi-Anger expansion on the complete outgoing laser electric field intensity E to obtain a cumulative sum of infinite harmonic terms based on a Bessel function in an approximate-free manner;
• step 5:
• extracting an outgoing laser electric field intensity Ek′ of kth-order comb teeth from the cumulative sum;
• step 6:
• obtaining an outgoing laser light intensity Ik of the kth-order comb teeth, and performing a spectral analysis of the intracavity electro-optic modulation type optical frequency comb in accordance with the outgoing laser light intensity Ik;
• step 7:
• determining a current working state of the light source by comparing a measured spectrum of the intracavity electro-optic modulation type optical frequency comb based on the spectral analysis and simulation results of a spectral envelope curve;
• and
• step 8:
• adjusting a physical parameter of the intracavity electro-optic modulation type optical frequency comb based on the current working state, wherein the physical parameter is selected from a group consisting of:
• (1) the incident laser frequency;
• (2) the intracavity electro-optic modulation frequency;
• (3) the intracavity material dispersion;
• and
• (4) a geometric length of the resonant cavity.