6533b7dbfe1ef96bd126fdd7
RESEARCH PRODUCT
Free-motion beam propagation factor measurement by means of a liquid crystal SLM
Raúl Martínez-cuencaPedro AndrésJesús LancisJ. Perez-vizcainoLluís Martínez-leónOmel Mendoza-yerosubject
PhysicsBeam diameterbusiness.industryBeam parameter productlaw.inventionLens (optics)OpticslawContinuous waveFocal lengthM squaredLaser beam qualitybusinessBeam (structure)description
We propose a compact and robust method to measure beam propagation factor (M2) of continuous wave (cw) laser beams. In contrast to the conventional scanning procedure described in the ISO/DIS 11146 standard, our proposal takes advantage of the features of programmable liquid crystal spatial light modulators (SLMs) where a lens is codified. Then, by using a CCD at a fixed position, the beam width according to the second order moment of the irradiance is determined for each focal length of the codified lenses. After adjusting the measured data to the theoretical focusing behavior of a real laser beam, the beam propagation factor is obtained. The proposed method was successfully validated in the laboratory where a full digital control of the measurement procedure was implemented. The M2 is from a very low time-consuming calculation. Its application to compact Optics systems is straightforward.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2011-06-01 | 2011 10th Euro-American Workshop on Information Optics |