Nonplanar surface structures of inorganic materials fabricated by femtosecond laser lithography

H. Nishiyama; M. Mizoshiri; J. Nishii; Y. Hirata

doi:10.1117/12.762542

12 February 2008 Nonplanar surface structures of inorganic materials fabricated by femtosecond laser lithography

H. Nishiyama, M. Mizoshiri, J. Nishii, Y. Hirata

Proceedings Volume 6883, Advanced Fabrication Technologies for Micro/Nano Optics and Photonics; 68830E (2008) https://doi.org/10.1117/12.762542
Event: MOEMS-MEMS 2008 Micro and Nanofabrication, 2008, San Jose, California, United States

Abstract

Silica-based nonplanar surface structures were fabricated by use of femtosecond laser lithography-assisted micromachining (FLAM), which is a combined process of femtosecond laser lithography and plasma etching. Diffractive optical elements (DOEs) are widely used for photonic applications such as optical pickup, interconnection and so forth. Most DOEs have been produced by semiconductor fabrication process. Although this process is useful to form complicated fine structures, there exist two problems. First, it is rather difficult to fabricate nonplanar surfaces including slopes and curves, which is effective to enhance diffraction efficiencies of DOEs. Second, microstructures cannot be fabricated onto nonplanar substrates. In the FLAM, nonplanar patterns are directly written inside resists by use of femtosecond laser-induced nonlinear optical absorption. Then, the patterns are transferred to underlying silica glasses by CHF₃ plasma. By use of FLAM, we successfully fabricated silica-based microFresnel lenses including curves and slopes on planar substrates and cross-grating structures onto a convex microlens. In particular, as for the latter, uniform grating structures with smooth surfaces were observed even at top and curved regions of the lenses. The FLAM is expected to be useful for the fabrication of highly functional DOEs such as diffractive/refractive hybrid microlenses.

Citation Download Citation

H. Nishiyama, M. Mizoshiri, J. Nishii, and Y. Hirata "Nonplanar surface structures of inorganic materials fabricated by femtosecond laser lithography", Proc. SPIE 6883, Advanced Fabrication Technologies for Micro/Nano Optics and Photonics, 68830E (12 February 2008); https://doi.org/10.1117/12.762542

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available