Optical Design and Engineering

Deastigmatism, circularization, and focusing of a laser diode beam using a single biconvex microlens

[+] Author Affiliations
Md. Nazmul Hasan, Muttahid-Ull Haque, Yung Chun Lee

National Cheng Kung University, Department of Mechanical Engineering, No. 1 University Road, Tainan 701, Taiwan

Opt. Eng. 55(9), 095107 (Sep 29, 2016). doi:10.1117/1.OE.55.9.095107
History: Received July 11, 2016; Accepted September 7, 2016
Text Size: A A A

Abstract.  A single biconvex microlens is proposed to correct the astigmatism and ellipticity of a laser diode (LD) beam and focus it to a smallest circular spot. The microlens has three different profiles in which one cylindrical input surface is to collimate the beam in the fast-axis (y-axis) direction. Output surface, on the other hand, holds two different parabolic profiles in fast- and slow-axis (x-axis) directions to correct the astigmatism and focus the beam into a smallest circular spot. A simulation software is used to design and optimize those lens profiles. Theoretically, the smallest focused spot size is around 4.24  μm in diameter. The three profiles are then transferred to photo-masks to fabricate the microlens on polycarbonate material using an excimer laser dragging method with alignment accuracy of 1  μm. The machined microlens is assembled with the LD using double-sided optically clear adhesive tape. The experimental focused spot is found to be 16.75  μm in diameter. Circularity of the focused spot is demonstrated by a single-shot exposure test on thin photoresist layer that shows a circular-dot diameter of 7.32  μm. The proposed technique has great potential in applications such as beam pen lithography, fiber coupling, and optical read-write head.

Figures in this Article
© 2016 Society of Photo-Optical Instrumentation Engineers

Citation

Md. Nazmul Hasan ; Muttahid-Ull Haque and Yung Chun Lee
"Deastigmatism, circularization, and focusing of a laser diode beam using a single biconvex microlens", Opt. Eng. 55(9), 095107 (Sep 29, 2016). ; http://dx.doi.org/10.1117/1.OE.55.9.095107


Tables

Access This Article
Sign in or Create a personal account to Buy this article ($20 for members, $25 for non-members).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

Related Book Chapters

Topic Collections

Advertisement
  • Don't have an account?
  • Subscribe to the SPIE Digital Library
  • Create a FREE account to sign up for Digital Library content alerts and gain access to institutional subscriptions remotely.
Access This Article
Sign in or Create a personal account to Buy this article ($20 for members, $25 for non-members).
Access This Proceeding
Sign in or Create a personal account to Buy this article ($15 for members, $18 for non-members).
Access This Chapter

Access to SPIE eBooks is limited to subscribing institutions and is not available as part of a personal subscription. Print or electronic versions of individual SPIE books may be purchased via SPIE.org.