Kester Robert T, Christenson Todd, Kortum Rebecca Richards, Tkaczyk Tomasz S
Department of Bioengineering, Rice University, 6100 Main Street, Houston, Texas 77005, USA.
Appl Opt. 2009 Jun 20;48(18):3375-84. doi: 10.1364/ao.48.003375.
The most expensive aspects in producing high quality miniature optical systems are the component costs and long assembly process. A new approach for fabricating these systems that reduces both aspects through the implementation of self-aligning LIGA (German acronym for lithographie, galvanoformung, abformung, or x-ray lithography, electroplating, and molding) optomechanics with high volume plastic injection molded and off-the-shelf glass optics is presented. This zero alignment strategy has been incorporated into a miniature high numerical aperture (NA = 1.0 W) microscope objective for a fiber confocal reflectance microscope. Tight alignment tolerances of less than 10 microm are maintained for all components that reside inside of a small 9 gauge diameter hypodermic tubing. A prototype system has been tested using the slanted edge modulation transfer function technique and demonstrated to have a Strehl ratio of 0.71. This universal technology is now being developed for smaller, needle-sized imaging systems and other portable point-of-care diagnostic instruments.