Design of GaN convex diffractive microlenses

✍ Scribed by Chii-Chang Chen; Jenq-Yang Chang; Gou-Chung Chi

• Book ID: 104159745
• Publisher: Elsevier Science
• Year: 2002
• Tongue: English
• Weight: 226 KB
• Volume: 34
• Category: Article
• ISSN: 0030-3992
• DOI: 10.1016/s0030-3992(02)00073-7

✦ Synopsis

In this work, convex di ractive microlenses are designed for fabrication in GaN-based material with a gray-level mask. The aspect ratios of the surface relief of plano-convex and double-convex microlenses for di erent numerical apertures are compared to reduce the fabrication di culty. The results show that for the numerical aperture less than 0.6, the aspect ratio of the double-convex di ractive microlenses is around half of the plano-convex di ractive microlenses. For the numerical aperture higher than 0.6, the aspect ratio of the plano-convex di ractive microlenses is similar to the double-convex di ractive microlenses. The error of the surface relief of the microlens occurring during the fabrication process is also discussed.