Frequency Addressing Method For Large Arrays Of Mechanical Structures
- Technology Benefits
- Greater dynamic rangeRobust opticsLow cost fabrication
- Technology Application
- This frequency addressing method is applicable to all large arrays of mechanical structures including Shack-Hartmann optical wavefront sensors.
- Detailed Technology Description
- None
- Supplementary Information
- Patent Number: US7355793B2
Application Number: US2005133455A
Inventor: Choo, Hyuck | Muller, Richard S.
Priority Date: 19 May 2004
Priority Number: US7355793B2
Application Date: 18 May 2005
Publication Date: 8 Apr 2008
IPC Current: G02B002710 | B29D001100 | G02B002600 | G02B002608 | G02B002709 | G02B002746 | G02F000100
US Class: 359619 | 359237
Assignee Applicant: The Regents of the University of California
Title: Optical system applicable to improving the dynamic range of Shack-Hartmann sensors
Usefulness: Optical system applicable to improving the dynamic range of Shack-Hartmann sensors
Summary: In Shack-Hartmann sensor used for monitoring and correcting continuously light beam distortion or wavefront aberration in ophthalmic analysis system in laser-assisted in-situ keratomileusis (LASIK) surgery, adaptive optics system for astronomy to improve image quality of astronomical telescope.
Novelty: Micro lens array for Shack-Hartmann sensor, has several detectors which detect moving of focal points of micro-lenses supported on support carriage
- Industry
- Biomedical
- Sub Category
- Medical Device
- Application No.
- 7355793
- Others
-
Tech ID/UC Case
17339/2004-032-0
Related Cases
2004-032-0
- *Abstract
-
Shack-Hartmann (SH) sensors are used in a growing number of optical wavefront applications, however the conventional design of these sensors limits their dynamic range, and consequently they produce false results if the curvature of the measured wave-front is too large. To overcome this dynamic-range limitation, designers have tried a modified unwrapped algorithm, a microlens array with well-defined astigmatism, and a spatial-light modulator as a shutter for the array. Unfortunately, the first two methods are not practical as they only work with a very limited set of wavefronts; and the third method is also impractical as it absorbs too much of the light, increases noise in the measurement, introduces additional aberrations, and is prohibitively expensive.
To address this problem, researchers at the University of California, Berkeley have developed a MEMS-based microlens array with a dramatically improved dynamic range. While the dynamic range of conventional SH sensor designs are limited by the size of the sub-apertures (usually 40 pixels), the dynamic range of this innovative Berkeley design is only limited by the size of entire sensing array and by the numerical aperture of the microlens.
This new SH system is cost-effective as the microlens array is batch-fabricated and the sensor does not require expensive components such as a spatial-light modulator. The sensor is also optically robust because the measured wavefront only needs to pass through a the low-aberration microlens and a very flat, thin silicon nitride membrane with a minimal reflection coefficient.
- *IP Issue Date
- Apr 8, 2008
- *Principal Investigator
-
Name: Hyuck Choo
Department:
Name: Richard Muller
Department:
- Country/Region
- USA
