Fabrication and characterization of microlens arrays on soda-lime glass using a combination of laser direct-write and thermal reflow techniques

We describe a hybrid technique for fabricating microlens arrays on soda-lime glass substrates composed by a direct-laser write and a post thermal treatment. In particular we use a nanosecond Q-Switch Nd: YVO(4) laser and a mufla Heraeus furnace working in the range of 620 degrees C-670 degrees C. An improvement in the quality of the microlens arrays were obtained as temperature increases, reducing their optical aberrations, surface roughness and increasing their resemblance. In particular at 670 degrees C we obtain high quality microlens array with diameter 47.89 + - 6.65 mu m; focal length 510610 mu m; focal spot size 2.82 + - 0.02 mu m; a root mean square of the total aberration lambda 28 + - lambda 77, strehl ratio 0.9475 + - 0.0352 and depth of focus 16.438 + - 5.762 mu m. Our results show the reliability of the combination of the Laser-direct writing technique with thermal treatment for fabricating high quality microlens arrays. (C) 2011 American Institute of Physics. [doi:10.1063 1.3609085]