High-speed linear frequency-sweeping laser source

Abstract

The invention discloses a high-speed linear frequency-sweeping laser source. The high-speed linear frequency-sweeping laser source comprises a tunable laser, a first optical switch, a polarization controller and a frequency shift ring, wherein the frequency shift ring is formed by sealing a first input port and a first output port of an optical fiber coupler; an optical isolator, a frequency shifting device, an optical amplifier, a second optical switch, a band-pass filter and the polarization controller are successively connected in series in the frequency shift ring through an optical fiber; then pulsed laser enters the optical fiber coupler; the laser is split in the optical fiber coupler; part of optical signals are directly output by a second output port of the optical fiber coupler; the other part of the optical signals are subjected to frequency shift again in the frequency shifting ring through the first output port of the optical fiber coupler; the optical signals subjected to frequency shift are split again by the optical fiber coupler. The process is recycle repeatedly; the frequency shift of laser is achieved in each cycle; the laser is output at different time, so that the high-speed, single-direction and K-space linear output of the frequency-sweeping laser with discrete wavelength, tunable wavelength interval and extremely narrow instant line width is achieved.

Description

technical field [0001] The invention relates to the field of frequency-sweeping laser source design, in particular to a high-speed linear frequency-sweeping laser source based on a frequency-shifting ring. Background technique [0002] Since the optical coherence tomography (OCT) technology was proposed in 1991, it has been rapidly applied to ophthalmology, skin, cardiovascular and other medical fields due to its incomparable advantages over other existing medical imaging technologies. Compared with the traditional OCT technology, the imaging speed of the swept-frequency OCT (SS-OCT) system using a swept-frequency laser light source is not limited by the detection system, which can achieve faster scanning. In the SS-OCT system, the performance of the frequency-swept laser source determines the performance level of the entire system. [0003] Frequency-swept lasers can be roughly divided into traditional frequency-swept lasers, Fourier-domain mode-locked lasers, and dispersi...

AI Technical Summary

Problems solved by technology

However, the frequency-swept output of Fourier domain mode-locked lasers has three major disadvantages: K-space nonlinearity, bidirectional scanning, and wide instantaneous linewidth

However, with the increase of frequency sweep speed, the instantaneous line width of the frequency sweep laser continues to widen, resulting in a decrease in imaging depth

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