Facile fabrication of optical diffusers by ablation-assisted nanosecond laser micromachining of glass substrates

Optical diffusers are essential components in modern technologies such as liquid crystal displays (LCDs), light emitting diodes (LEDs), imaging systems, etc., and a facile, quick, and cost effective fabrication technique is highly desired. Among the various known techniques femtosecond laser micromachining of glass substrates is known to work well for this purpose at the expense of high fabrication cost. On the other hand, low-cost nanosecond laser micromachining at 1064 nm does not always work well for most of the commonly used glass substrates. We demonstrate that this dilemma can be easily solved by ablation-assisted nanosecond laser micromachining of glass, where a metal target is placed just behind the glass substrate and the nanosecond laser is focused to the metal target through the glass so that the back surface of the glass substrate is efficiently etched by ablation fragments and plasma of the metal target. By varying the laser parameters and the gap between the glass and metal target we can control the optical properties of the fabricated diffusers. We also demonstrate that laser cleaning is an efficient way to remove all deposits after laser micromachining. All those results indicate that the demonstrated technique is a facile, quick, and cost effective fabrication method of optical diffusers.

Automated summary

Optical diffusers are essential in modern technologies and a cheap fabrication technique is desired. By using ablation-assisted nanosecond laser micromachining with a metal target behind the glass substrate, the optical properties of the diffusers can be controlled. Laser cleaning is also shown to be an efficient method for removing deposits after micromachining. The demonstrated technique is a quick, cost effective way for fabricating optical diffusers.