Massachusetts Institute of Technology

David Crompton

Alexander Stolyarov

Thomas H Jeys

William D Herzog

Shawn Michael Redmond

Brian G Saar

Ryan Sullenberger

Michael H Valois

Alexander M Stolyarov

A device, and corresponding method, can include a pump light source configured to irradiate a target specimen. The device can also include a sensor configured to observe a probe speckle pattern based on light from a probe light source reflected from the target specimen. The device further may include a correlator configured to determine a material property of the target specimen by analyzing changes in images of the probe speckle pattern as a function of the irradiation with the pump light source. Advantages of the device and method can include much higher sensitivity than existing methods; the ability to use visible probe wavelengths for uncooled, low-cost visible detectors with high spatial resolution; and the ability to obtain target material properties without detecting infrared light.

Material property determination using photothermal speckle detection

A device, and corresponding method, can include a pump light source configured to be modulated at a pump modulation and to irradiate a target specimen. The device can also include a probe light source arranged to generate a speckle pattern from the target specimen, as well as a sensor configured to detect changes in at least one of position and intensity of one or more speckle lobes of the speckle pattern having correlation with the pump modulation. The device and method can be used for non-contact monitoring and remote sensing of surfaces, gases, liquids, particles, and other target materials by analyzing speckle pattern changes as a function of pump light irradiation. Advantages can include much higher sensitivity than existing methods; the ability to use visible probe wavelengths for uncooled, low-cost visible detectors with high spatial resolution; and the ability to obtain target material properties without detecting infrared light.

Devices and methods for sensing targets using photothermal speckle detection

A micro-optic module couples a pair of substrates to opposing sides of a fast-axis collimating lens and a beam twister. The arrangement of optical elements is oriented substantially parallel to a neutral plane defined by propagation paths of the light from each emitter of an array of laser emitters. The pair of substrates may have substantially the same coefficient of thermal expansion and coefficient of thermal conductivity, and the micro-optic module may be configured to exhibit symmetry of thermal loading about the neutral plane when the array of laser emitters emits light at an operational power level. The micro-optic module may be coupled with an array of laser emitters, for example a laser diode bar. The module exhibits thermal properties that facilitate a consistently focused light beam with minimal positional drift, which may enable efficient and reliable coupling of the light beam to optical fibers and other high-tolerance applications.

Symmetric micro-optic module

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Lowell, MA, United States of America

David Crompton