Femtojoule class pulsed laser light source

Abstract

The invention discloses a joule-level pulse laser light source which comprises a laser, a collimating mirror, a beam splitter, an energy monitor meter, a polarizer component, a fixed attenuator component, a reference energy meter, a variable attenuator, a beam expander and a computer. Light emitted by the laser passes through the collimating mirror and is changed into parallel light, the parallel light is split into two beams through the beam splitter, the reflective light beam is received and detected by the energy monitor meter, the computer judges whether the laser emits light stably or not according to the detection value of the energy monitor meter, the transmission light beam passes through the polarizer component and the fixed attenuator component and is changed into attenuate linearly polarized light, and the attenuate linearly polarized light is attenuated to a required energy value through the variable attenuator with transmittance controlled by the computer and is finally output by the beam expander. The joule-level pulse laser light source solves the problem of simulating long-distance diffuse reflection echo signals in a measurement test, and the provided analog light beams have the advantages of being uniform and stable in energy.

Description

technical field [0001] The invention belongs to the technical field of optical metrology, and mainly relates to a pulsed laser light source, in particular to a femtojoule level pulsed laser light source with continuously adjustable intensity. Background technique [0002] In the fields of radar early warning, laser ranging, laser tracking, laser guidance and other fields, the diffuse reflection echo signals of long-distance targets are very weak, and the energy value is generally in femtojoules (1 femtojoule is equal to 10 －15 Joule) level, in the process of scientific research and production of corresponding equipment and products, it is necessary to measure and calibrate their performance. At this time, a light source that can provide femtojoule-level weak light is needed to simulate the diffuse reflection echo signal, and the existing laser can provide The lowest energy value is around ten picojoules (i.e. 10 －11 Joule) level, so it is necessary to design such a light so...

AI Technical Summary

Problems solved by technology

The disadvantage of this solution is that the stepless attenuator is manually adjusted and cannot provide accurate values. At the same time, there are insurmountable defects in the stepless attenuator, that is, for large-aperture beams, the attenuation ratios of different positions of the beam after passing through the attenuator are different. Not the same, the uniformity of the output beam cannot be guaranteed; in addition, the transmittance of the neutral attenuator is more accurate when it works above the μJ energy level, but the transmittance will change under the weak light of the fJ energy level, and the existing detection The detector can only detect light with a light intensity of hundreds of femtojoules, so the transmittance of the neutral attenuator of this scheme cannot be calibrated and verified in actual work

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