Rapid K-space linear frequency sweep laser source

Abstract

The invention discloses a rapid K-space linear frequency sweep laser source. The laser source comprises a semiconductor optical amplifier, two polarization controllers, a dispersion control delay line, a circulator, a tuned filter and an output optical fiber coupler, wherein radiation light emitted from the semiconductor optical amplifier is transmitted to the dispersion control delay line through a polarization controller I; the middle port of the circulator is connected to the tuned filer through a first port of the circulator; returned signals are connected to the optical fiber coupler after passing through a third port of the circulator; one path of the optical fiber coupler outputs frequency sweep laser through a 60% port, and the other path of the optical fiber coupler is connected to the polarization controller II and then returns to a ring laser oscillation cavity; the tuned filter mainly comprises two dispersion elements, namely a grating and a prism, and a rotary polygonal mirror; and the linearity of a wave number space is achieved through combination of linear dispersion of the grating and non-linear dispersion of the prism as well as selection on the angles and directions of the prism. The rapid K-space linear frequency sweep laser source can be used for outputting the rapid K-space linear frequency sweep laser, and can obtain the signals of the linearity of the wave number space directly without calibration when being applied to an OCT (Optical Coherence Tomography) imaging system.

Description

technical field [0001] The invention relates to the technical field of frequency-sweeping optical coherence tomography, in particular to a fast K-space linear frequency-sweeping laser light source. Background technique [0002] Optical coherence tomography (OCT) is a non-destructive "optical biopsy" technology of coherence domain optical imaging. Frequency-sweeping OCT obtains information within a range of imaging depths within a frequency-sweeping period, thereby greatly improving imaging speed, signal-to-noise ratio, and sensitivity. Sweep-frequency OCT realizes real-time imaging and is applied to in vivo biomedical diagnosis. [0003] The output wavelength of the frequency sweep spectrum of the traditional frequency sweep light source is linear, and the wavenumber does not have a strict linear relationship with time. The nonlinearity of the sampling of the interference spectrum in the wavenumber space will lead to the decline of the axial resolution. Spatial linear corr...

AI Technical Summary

Problems solved by technology

These methods all require the introduction of additional calibration equipment, resulting in an increase in cost

Kim et al. of South Korea adopted a parabolic slit design. After the grating splits light, it passes through a parabolic slit and then reaches the mirror to realize the linear conversion from wavelength to K-space linearity. However, this method results in very low resolution.

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