Exotic Ultrasonics for the real world

Custom CMOS modulated light cameras for parallel detection in picosecond ultrasonics

We have developed a custom CMOS linear array detector for picosecond ultrasound measurements. Performing many measurements in parallel allows us to dramatically reduce the time it takes to perform each measurement.

The signals we are interested in are tiny fluctuations on a large DC background, these types are signals are typically extracted by modulating the signal of interest and using a lock in technique.

The linear array camera we have developed, consists of a line of active pixel sensors, each one has a very large photon capacity to allow it to reach the high signal to noise ratios required to enable us to see the tiny signals present in our experiments. Each pixel has four charge storage areas for capturing four samples during one modulation cycle. Demodulating these samples allows us to measure the amplitude and phase of our signals. The cameras can be locked to a wide range of modulation frequencies.

This new detector allows imaging of sample properties, such as coating thickness, over large areas where previously only point measurements were feasible. These camera have allowed us to reduce experiment time by over 30 times compared to the single point detector approach.

Related publications

R J Smith, R A Light, N Johnston, S Sharples, M C Pitter, M G Somekh - Parallel detection in laser ultrasonics

Journal of Physics: Conference Series 214:012006,2010

http://dx.doi.org/10.1088/1742-6596/214/1/012006
Bibtex<div>Author : R J Smith, R A Light, N Johnston, S Sharples, M C Pitter, M G Somekh
Title : Parallel detection in laser ultrasonics
In : Journal of Physics: Conference Series -
Address :
Date : 2010
</div>

Richard J. Smith, Roger A. Light, Steve D. Sharples, Nicholas S. Johnston, Mark C. Pitter, Mike G. Somekh - Multichannel, time-resolved picosecond laser ultrasound imaging and spectroscopy with custom complementary metal-oxide-semiconductor detector

Review of Scientific Instruments 81(2):024901,2010

http://dx.doi.org/10.1063/1.3298606
Bibtex<div>Author : Richard J. Smith, Roger A. Light, Steve D. Sharples, Nicholas S. Johnston, Mark C. Pitter, Mike G. Somekh
Title : Multichannel, time-resolved picosecond laser ultrasound imaging and spectroscopy with custom complementary metal-oxide-semiconductor detector
In : Review of Scientific Instruments -
Address :
Date : 2010
</div>

R J Smith, M G Somekh, S D Sharples, M C Pitter, I Harrison - Parallel detection of low modulation depth signals: application to picosecond ultrasonics

Measurement Science and Technology 19(5):055301,2008

http://dx.doi.org/10.1088/0957-0233/19/5/055301
Bibtex<div>Author : R J Smith, M G Somekh, S D Sharples, M C Pitter, I Harrison
Title : Parallel detection of low modulation depth signals: application to picosecond ultrasonics
In : Measurement Science and Technology -
Address :
Date : 2008
</div>

Roger A. Light, Richard J. Smith, Nicholas S. Johnston, Steve D. Sharples, Michael G. Somekh, Mark C. Pitter - Highly parallel CMOS lock-in optical sensor array for hyperspectral recording in scanned imaging systems

pp. 75700U--75700U-10, San Francisco, California, {USA},2010

http://dx.doi.org/10.1117/12.842083
Bibtex<div>Author : Roger A. Light, Richard J. Smith, Nicholas S. Johnston, Steve D. Sharples, Michael G. Somekh, Mark C. Pitter
Title : Highly parallel CMOS lock-in optical sensor array for hyperspectral recording in scanned imaging systems
In : -
Address : San Francisco, California, {USA}
Date : 2010
</div>

Richard Smith, Mike Somekh, Steve Sharples, Mark Pitter, Roger Light, Nicholas Johnston - Parallel detection in picosecond ultrasonics with both commercial and custom array detection

1st International Symposium on Laser Ultrasonics: Science, Technology and Applications ,2008

http://www.ndt.net/article/laser-ut2008/toc.php
Bibtex

Author : Richard Smith, Mike Somekh, Steve Sharples, Mark Pitter, Roger Light, Nicholas Johnston
Title : Parallel detection in picosecond ultrasonics with both commercial and custom array detection
In : 1st International Symposium on Laser Ultrasonics: Science, Technology and Applications -
Address :
Date : 2008