Table 2.

Characteristic of PDL fabrication technique. (a) Direct writing based, (b) interference lithography-based manufacturing, and (c) lithography-based

Description	Laser direct witting		Interference lithography		Lithography
Conceptual Figures
Patterning Resolution	Tens of μm (pulse laser) Hundreds of nm (fs laser)	Medium	Hundreds of nm	Medium	Tens of nm	High
Process Complexity	Single step process, ambient environment, tunable laser and optomechanical parameters	Low	Single step process, ambient environment, tunable laser and optomechanical parameters	Medium	Multi-stage process, mask preparation, chemical etching	High
Design Flexibility	Digital pattern easily converted actual	High	Low capability to change of design. Complex optical setup to achieve interference	Low	Pre-mask preparation to convert to design to actual	Medium
Productivity	Single-point processing	Low	Large area processing	High	Large area processing	High
Investment Cost	Small-area facility with low environmental requirement, simple pattering equipment setup	Medium	Small-area facility with low environmental requirement, complex opto-mechanical setup (to cater irregular pattern)	Medium	Multi-equipment setup with high environmental and chemical management	High