The term 'microoptics' comprises two features: firstly, it relates to the fact the dimensions of the optical elements are usually small, typically, on the order of 1 mm an less. Secondly, and more characteristic, is the use of microfabrication techniques as known from the processing of electronic circuits. There exists a variety of fabrication techniques used for microoptic fabrication. The foundation of microfabrication is the lithographic process which is used for structuring a layer of photoresist. One can distinguish between conventional mask-based optical lithography and maskless direct-write techniques using laser and electron beam writers. Transfer of the photoresist pattern into a substrate can be achieved by etching or milling. For combining passive optical elements or systems with electronic, optoelectronic, or micromechanic devices, hybrid integration techniques are used like flip-chip bonding and anodic bonding.

At the ONT group, the following equipment is used for microoptic fabrication:

Mask Aligners:	Karl Suess MJB 3 and MA 4
Reactive Ion Etcher:	Oxford Plasmalab 80 Plus
Flip-Chip Bonder:	Research Devices M-8A
Anodic Bonder:	Süss ABM 6
Profilometer:	Veeco Dektak V200 i
Spinner:	Karl Suss RC8 Gyrset