Abstract
We describe a method of fabricating multilevel diffractive optics by excimer laser ablation. A portion of a chrome mask containing many patterns is illuminated by 193-nm laser light and imaged by an objective lens onto a poly(imide) substrate. Ablation of an entire single pattern is achieved in a single laser pulse. Multiple pulses are used to vary the ablation depth, and multiple patterns are used to create a variety of multilevel optics. We have successfully fabricated arrays of eight-level diffractive microlenses with varying focal lengths and decenters. The optics performed with diffraction-limited focusing and neartheoretical diffraction efficiency (92%).
Original language | English (US) |
---|---|
Pages (from-to) | 4660-4665 |
Number of pages | 6 |
Journal | Applied Optics |
Volume | 36 |
Issue number | 20 |
DOIs | |
State | Published - Jul 10 1997 |
Keywords
- Ablation
- Binary optics
- Diffractive optics
- Excimer laser
- Laser machining
- Micro-optics
- Microlenses