Hollow cube-corner prism optical delay line device with endogenous scale light source

Abstract

The invention relates to a hollow cube-corner prism optical delay line device with an endogenous scale light source. The hollow cube-corner prism optical delay line device comprises a scale light source, a photoelectric sensor, an optical fiber coupler, a wavelength division multiplexer, collimators Z1 and Z2, plane reflecting mirrors F1 and F2, polarization controllers P1 and P2, a single-mode optical fiber, a rotary disk, hollow cube-corner prisms and a motor, wherein a scale light source signal is divided into two paths of light signals by the optical fiber coupler; the first path of light signals passes through the polarization controller P1 and the collimator Z1, is emitted to the plane reflecting mirror F1, returns along the same road and is received by the photoelectric sensor; and the second path of light signals passes through the polarization controller P2, the wavelength division multiplexer and the collimator Z2, is emitted to the hollow cube-corner prisms which are uniformly distributed on the rotary disk along the circumference, is guided for 180 DEG and then emitted to the plane reflecting mirror F2 and returns along the same road, and a returned signal is received by the photoelectric sensor and interferes with the first path of signals. The hollow cube-corner prism optical delay line device is simple in installation process and high in measuring speed, and signal to noise ratio and measuring accuracy are improved.

Description

technical field [0001] The invention relates to the field of optical instruments, in particular to ophthalmic optical equipment of optical delay lines, in particular to a hollow corner cube optical delay line device with an endogenous scale light source. Background technique [0002] The optical delay line is an optical device that changes the optical path or phase. In the measuring instruments that use the principle of interference, the optical delay line needs to change the optical path or phase, so that the optical path of the measurement optical path and the optical path of the reference optical path meet the interference conditions. to complete the measurement. Most of the optical interferometry techniques that have appeared in recent years are based on the principle of broadband light interference, and can be roughly divided into two categories: one uses partial coherence interferometer (PCI), and the other uses low coherence reflectometry (Low Coherence Refl. ectomet...

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Problems solved by technology

However, the change in the length of the delay line is caused by the rotation of the square prism. The delay length and the rotation angle are not linear, and calibration is required. The calibration process is complicated. The calibration result has a lot to do with the uniformity of the rotation of the square prism.

[0005] The delay line technology in the above instruments, such as the delay line in the patent US5673096A, is affected by the linear motion speed, needs to start and stop acceleration and deceleration processing, the measurement speed is slow, only one parameter is measured at a time, and other external measurement devices are required for the measurement of the moving distance; the patent In the delay line technology mentioned in US20090268209A, when the incident light beam enters the rotating square prism, it needs to go through eight times of transmission and reflection, and the return light ratio (ratio of the output light to the incident light power) is seriously reduced, which reduces the signal-to-noise ratio

[0006] For the delay line technology in the above two instruments, the incident light needs to be transmitted and reflected inside the right-angle prism or square prism. Due to the influence of the refractive index of the prism material, the dispersion effect is aggravated. The posture is not easy to guarantee and requires precise adjustment, and the longer the delay line is, the more difficult it is to obtain a delayed signal with a stable light return ratio

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