Blinn College

Part-Time Physics Instructor

Michael worked at Blinn College as a Part-Time Physics Instructor

Rice University

Instructor of Physics and Astronomy

Michael worked at Rice University as a Instructor of Physics and Astronomy

Discover, Enjoy and Explore Physics and Engineering (DEEP) Program

Graduate Mentor

In the program we mentor undergraduate students in the design, development, and presentation of physics demonstrations. These demos are then used in local Physics Shows, and at the annual Physics and Engineering Festival.

Texas A&M University

Graduate Research Assistant

Ph.D. Advisor: Edward S. Fry
Dissertation Topic: A New Diffuse Reflecting Material with Applications Including Integrating Cavity Ring-Down Spectroscopy

My primary research involved the development and use of a novel diffuse reflector material for various types of applied optics and spectroscopy applications. In particular, I have the led the development of a new type of integrating cavity absorption spectroscopy involving the temporal decay of the light in the cavity. This provides a very sensitive technique for measuring absorption coefficients, even when the sample produces strong scattering. More recently, I have also been involved in a number of projects that use our diffuse reflector material for a variety of biomedical applications.

Texas A&M University

Postdoctoral Researcher

Michael worked at Texas A&M University as a Postdoctoral Researcher

Tri-Services Research Laboratory

Visiting Researcher

Multiple visits for a collaborative research project dealing with measuring the optical absorption of biological materials with a novel high-reflectivity integrating cavity. This technique is particularly useful when dealing with samples that produce a large amount of scattered light.

Diffuse Reflecting Material for Integrating Cavity Spectroscopy - Including Ring-Down Spectroscopy

Applied Optics

Abstract: We report the development of a diffuse reflecting material with measured reflectivity values as high as 0.99919 at 532 nm and 0.99686 at 266 nm. This material is a high-purity fumed silica, or quartz powder, with particle sizes on the order of 40 nm. We demonstrate that this material can be used to produce surfaces with nearly Lambertian behavior, which in turn can be used to form the inner walls of high-reflectivity integrating cavities. Light reflecting off such a surface penetrates into the material. This means there will be an effective “wall time” for each reflection off the walls in an integrating cavity. We measure this wall time and show that it can be on the order of several picoseconds. Finally, we introduce a technique for absorption spectroscopy in an integrating cavity based on cavity ring-down spectroscopy. We call this technique integrating cavity ring-down spectroscopy.

Diffuse Reflecting Material for Integrating Cavity Spectroscopy - Including Ring-Down Spectroscopy

Applied Optics

Abstract: We report the development of a diffuse reflecting material with measured reflectivity values as high as 0.99919 at 532 nm and 0.99686 at 266 nm. This material is a high-purity fumed silica, or quartz powder, with particle sizes on the order of 40 nm. We demonstrate that this material can be used to produce surfaces with nearly Lambertian behavior, which in turn can be used to form the inner walls of high-reflectivity integrating cavities. Light reflecting off such a surface penetrates into the material. This means there will be an effective “wall time” for each reflection off the walls in an integrating cavity. We measure this wall time and show that it can be on the order of several picoseconds. Finally, we introduce a technique for absorption spectroscopy in an integrating cavity based on cavity ring-down spectroscopy. We call this technique integrating cavity ring-down spectroscopy.

Measuring the Absorption Coefficient of Biological Materials Using Integrating Cavity Ring-Down Spectroscopy

Optica

Volume 2, Issue 2, pp. 162-168. Abstract: A number of imaging modalities rely on the exact knowledge of both the absorption and scattering properties of cells and organelles. We report a simple method for accurate and precise measurement of the optical absorption coefficient of biological samples, even in the presence of strong scattering. The technique is based on cavity ring-down spectroscopy, but the traditional mirrored cavity is replaced with a high-reflectivity integrating cavity. The Lambertian behavior of the cavity walls creates an isotropic field inside the cavity, thereby eliminating the effects of scattering in the sample. Thus, integrating cavity ring-down spectroscopy (ICRDS) provides a true, direct measurement of the absorption coefficient, as opposed to the net attenuation. We demonstrate the effectiveness of this technique by measuring the absorption coefficient of retinal pigmented epithelium cells. Furthermore, we demonstrate that ICRDS is insensitive to scattering effects using suspensions of copolymer microspheres and an absorbing dye solution. These results are compared with measurements made using a more traditional transmission-style setup. This technique will have an impact on the field of nanoscience, where optical characterization of nanoparticles is still done using a conventional spectrometer that is only capable of providing measurements of the extinction coefficient.

Diffuse Reflecting Material for Integrating Cavity Spectroscopy - Including Ring-Down Spectroscopy

Applied Optics

Abstract: We report the development of a diffuse reflecting material with measured reflectivity values as high as 0.99919 at 532 nm and 0.99686 at 266 nm. This material is a high-purity fumed silica, or quartz powder, with particle sizes on the order of 40 nm. We demonstrate that this material can be used to produce surfaces with nearly Lambertian behavior, which in turn can be used to form the inner walls of high-reflectivity integrating cavities. Light reflecting off such a surface penetrates into the material. This means there will be an effective “wall time” for each reflection off the walls in an integrating cavity. We measure this wall time and show that it can be on the order of several picoseconds. Finally, we introduce a technique for absorption spectroscopy in an integrating cavity based on cavity ring-down spectroscopy. We call this technique integrating cavity ring-down spectroscopy.

Measuring the Absorption Coefficient of Biological Materials Using Integrating Cavity Ring-Down Spectroscopy

Optica

Volume 2, Issue 2, pp. 162-168. Abstract: A number of imaging modalities rely on the exact knowledge of both the absorption and scattering properties of cells and organelles. We report a simple method for accurate and precise measurement of the optical absorption coefficient of biological samples, even in the presence of strong scattering. The technique is based on cavity ring-down spectroscopy, but the traditional mirrored cavity is replaced with a high-reflectivity integrating cavity. The Lambertian behavior of the cavity walls creates an isotropic field inside the cavity, thereby eliminating the effects of scattering in the sample. Thus, integrating cavity ring-down spectroscopy (ICRDS) provides a true, direct measurement of the absorption coefficient, as opposed to the net attenuation. We demonstrate the effectiveness of this technique by measuring the absorption coefficient of retinal pigmented epithelium cells. Furthermore, we demonstrate that ICRDS is insensitive to scattering effects using suspensions of copolymer microspheres and an absorbing dye solution. These results are compared with measurements made using a more traditional transmission-style setup. This technique will have an impact on the field of nanoscience, where optical characterization of nanoparticles is still done using a conventional spectrometer that is only capable of providing measurements of the extinction coefficient.

Bright Emission From A Random Raman Laser

Nature Communications

Diffuse Reflecting Material for Integrating Cavity Spectroscopy - Including Ring-Down Spectroscopy

Applied Optics

Abstract: We report the development of a diffuse reflecting material with measured reflectivity values as high as 0.99919 at 532 nm and 0.99686 at 266 nm. This material is a high-purity fumed silica, or quartz powder, with particle sizes on the order of 40 nm. We demonstrate that this material can be used to produce surfaces with nearly Lambertian behavior, which in turn can be used to form the inner walls of high-reflectivity integrating cavities. Light reflecting off such a surface penetrates into the material. This means there will be an effective “wall time” for each reflection off the walls in an integrating cavity. We measure this wall time and show that it can be on the order of several picoseconds. Finally, we introduce a technique for absorption spectroscopy in an integrating cavity based on cavity ring-down spectroscopy. We call this technique integrating cavity ring-down spectroscopy.

Measuring the Absorption Coefficient of Biological Materials Using Integrating Cavity Ring-Down Spectroscopy

Optica

Volume 2, Issue 2, pp. 162-168. Abstract: A number of imaging modalities rely on the exact knowledge of both the absorption and scattering properties of cells and organelles. We report a simple method for accurate and precise measurement of the optical absorption coefficient of biological samples, even in the presence of strong scattering. The technique is based on cavity ring-down spectroscopy, but the traditional mirrored cavity is replaced with a high-reflectivity integrating cavity. The Lambertian behavior of the cavity walls creates an isotropic field inside the cavity, thereby eliminating the effects of scattering in the sample. Thus, integrating cavity ring-down spectroscopy (ICRDS) provides a true, direct measurement of the absorption coefficient, as opposed to the net attenuation. We demonstrate the effectiveness of this technique by measuring the absorption coefficient of retinal pigmented epithelium cells. Furthermore, we demonstrate that ICRDS is insensitive to scattering effects using suspensions of copolymer microspheres and an absorbing dye solution. These results are compared with measurements made using a more traditional transmission-style setup. This technique will have an impact on the field of nanoscience, where optical characterization of nanoparticles is still done using a conventional spectrometer that is only capable of providing measurements of the extinction coefficient.

Bright Emission From A Random Raman Laser

Nature Communications

Measurement of the Absorption Coefficient of Biological Materials Using Integrating Cavity Ring-Down Spectroscopy

Conference Proceedings for Biomedical Optics (BIOMED) OSA

Diffuse Reflecting Material for Integrating Cavity Spectroscopy - Including Ring-Down Spectroscopy

Applied Optics

Abstract: We report the development of a diffuse reflecting material with measured reflectivity values as high as 0.99919 at 532 nm and 0.99686 at 266 nm. This material is a high-purity fumed silica, or quartz powder, with particle sizes on the order of 40 nm. We demonstrate that this material can be used to produce surfaces with nearly Lambertian behavior, which in turn can be used to form the inner walls of high-reflectivity integrating cavities. Light reflecting off such a surface penetrates into the material. This means there will be an effective “wall time” for each reflection off the walls in an integrating cavity. We measure this wall time and show that it can be on the order of several picoseconds. Finally, we introduce a technique for absorption spectroscopy in an integrating cavity based on cavity ring-down spectroscopy. We call this technique integrating cavity ring-down spectroscopy.

Measuring the Absorption Coefficient of Biological Materials Using Integrating Cavity Ring-Down Spectroscopy

Optica

Volume 2, Issue 2, pp. 162-168. Abstract: A number of imaging modalities rely on the exact knowledge of both the absorption and scattering properties of cells and organelles. We report a simple method for accurate and precise measurement of the optical absorption coefficient of biological samples, even in the presence of strong scattering. The technique is based on cavity ring-down spectroscopy, but the traditional mirrored cavity is replaced with a high-reflectivity integrating cavity. The Lambertian behavior of the cavity walls creates an isotropic field inside the cavity, thereby eliminating the effects of scattering in the sample. Thus, integrating cavity ring-down spectroscopy (ICRDS) provides a true, direct measurement of the absorption coefficient, as opposed to the net attenuation. We demonstrate the effectiveness of this technique by measuring the absorption coefficient of retinal pigmented epithelium cells. Furthermore, we demonstrate that ICRDS is insensitive to scattering effects using suspensions of copolymer microspheres and an absorbing dye solution. These results are compared with measurements made using a more traditional transmission-style setup. This technique will have an impact on the field of nanoscience, where optical characterization of nanoparticles is still done using a conventional spectrometer that is only capable of providing measurements of the extinction coefficient.

Bright Emission From A Random Raman Laser

Nature Communications

Measurement of the Absorption Coefficient of Biological Materials Using Integrating Cavity Ring-Down Spectroscopy

Conference Proceedings for Biomedical Optics (BIOMED) OSA

Ultrasensitive Detection of Waste Products in Water Using Fluorescence Emission Cavity Enhanced Spectroscopy

Proceedings of the National Academy of Sciences

Press articles on this research: http://www.washingtonpost.com/blogs/early-lead/wp/2014/05/08/new-detection-device-will-shame-you-if-you-pee-in-the-pool/ http://www.dailymail.co.uk/sciencetech/article-2622368/Dont-dare-pee-pool-Device-glows-green-water-contains-urine-faeces-using-lasers-react-waste.html

Diffuse Reflecting Material for Integrating Cavity Spectroscopy - Including Ring-Down Spectroscopy

Applied Optics

Abstract: We report the development of a diffuse reflecting material with measured reflectivity values as high as 0.99919 at 532 nm and 0.99686 at 266 nm. This material is a high-purity fumed silica, or quartz powder, with particle sizes on the order of 40 nm. We demonstrate that this material can be used to produce surfaces with nearly Lambertian behavior, which in turn can be used to form the inner walls of high-reflectivity integrating cavities. Light reflecting off such a surface penetrates into the material. This means there will be an effective “wall time” for each reflection off the walls in an integrating cavity. We measure this wall time and show that it can be on the order of several picoseconds. Finally, we introduce a technique for absorption spectroscopy in an integrating cavity based on cavity ring-down spectroscopy. We call this technique integrating cavity ring-down spectroscopy.

Measuring the Absorption Coefficient of Biological Materials Using Integrating Cavity Ring-Down Spectroscopy

Optica

Volume 2, Issue 2, pp. 162-168. Abstract: A number of imaging modalities rely on the exact knowledge of both the absorption and scattering properties of cells and organelles. We report a simple method for accurate and precise measurement of the optical absorption coefficient of biological samples, even in the presence of strong scattering. The technique is based on cavity ring-down spectroscopy, but the traditional mirrored cavity is replaced with a high-reflectivity integrating cavity. The Lambertian behavior of the cavity walls creates an isotropic field inside the cavity, thereby eliminating the effects of scattering in the sample. Thus, integrating cavity ring-down spectroscopy (ICRDS) provides a true, direct measurement of the absorption coefficient, as opposed to the net attenuation. We demonstrate the effectiveness of this technique by measuring the absorption coefficient of retinal pigmented epithelium cells. Furthermore, we demonstrate that ICRDS is insensitive to scattering effects using suspensions of copolymer microspheres and an absorbing dye solution. These results are compared with measurements made using a more traditional transmission-style setup. This technique will have an impact on the field of nanoscience, where optical characterization of nanoparticles is still done using a conventional spectrometer that is only capable of providing measurements of the extinction coefficient.

Bright Emission From A Random Raman Laser

Nature Communications

Measurement of the Absorption Coefficient of Biological Materials Using Integrating Cavity Ring-Down Spectroscopy

Conference Proceedings for Biomedical Optics (BIOMED) OSA

Ultrasensitive Detection of Waste Products in Water Using Fluorescence Emission Cavity Enhanced Spectroscopy

Proceedings of the National Academy of Sciences

Press articles on this research: http://www.washingtonpost.com/blogs/early-lead/wp/2014/05/08/new-detection-device-will-shame-you-if-you-pee-in-the-pool/ http://www.dailymail.co.uk/sciencetech/article-2622368/Dont-dare-pee-pool-Device-glows-green-water-contains-urine-faeces-using-lasers-react-waste.html

Measuring the Absorption Coefficient of Pure Water in the UV With an Integrating Cavity Absorption Meter

Conference Proceedings for Ocean Optics XXI

Diffuse Reflecting Material for Integrating Cavity Spectroscopy - Including Ring-Down Spectroscopy

Applied Optics

Abstract: We report the development of a diffuse reflecting material with measured reflectivity values as high as 0.99919 at 532 nm and 0.99686 at 266 nm. This material is a high-purity fumed silica, or quartz powder, with particle sizes on the order of 40 nm. We demonstrate that this material can be used to produce surfaces with nearly Lambertian behavior, which in turn can be used to form the inner walls of high-reflectivity integrating cavities. Light reflecting off such a surface penetrates into the material. This means there will be an effective “wall time” for each reflection off the walls in an integrating cavity. We measure this wall time and show that it can be on the order of several picoseconds. Finally, we introduce a technique for absorption spectroscopy in an integrating cavity based on cavity ring-down spectroscopy. We call this technique integrating cavity ring-down spectroscopy.

Measuring the Absorption Coefficient of Biological Materials Using Integrating Cavity Ring-Down Spectroscopy

Optica

Volume 2, Issue 2, pp. 162-168. Abstract: A number of imaging modalities rely on the exact knowledge of both the absorption and scattering properties of cells and organelles. We report a simple method for accurate and precise measurement of the optical absorption coefficient of biological samples, even in the presence of strong scattering. The technique is based on cavity ring-down spectroscopy, but the traditional mirrored cavity is replaced with a high-reflectivity integrating cavity. The Lambertian behavior of the cavity walls creates an isotropic field inside the cavity, thereby eliminating the effects of scattering in the sample. Thus, integrating cavity ring-down spectroscopy (ICRDS) provides a true, direct measurement of the absorption coefficient, as opposed to the net attenuation. We demonstrate the effectiveness of this technique by measuring the absorption coefficient of retinal pigmented epithelium cells. Furthermore, we demonstrate that ICRDS is insensitive to scattering effects using suspensions of copolymer microspheres and an absorbing dye solution. These results are compared with measurements made using a more traditional transmission-style setup. This technique will have an impact on the field of nanoscience, where optical characterization of nanoparticles is still done using a conventional spectrometer that is only capable of providing measurements of the extinction coefficient.

Bright Emission From A Random Raman Laser

Nature Communications

Measurement of the Absorption Coefficient of Biological Materials Using Integrating Cavity Ring-Down Spectroscopy

Conference Proceedings for Biomedical Optics (BIOMED) OSA

Ultrasensitive Detection of Waste Products in Water Using Fluorescence Emission Cavity Enhanced Spectroscopy

Proceedings of the National Academy of Sciences

Press articles on this research: http://www.washingtonpost.com/blogs/early-lead/wp/2014/05/08/new-detection-device-will-shame-you-if-you-pee-in-the-pool/ http://www.dailymail.co.uk/sciencetech/article-2622368/Dont-dare-pee-pool-Device-glows-green-water-contains-urine-faeces-using-lasers-react-waste.html

Measuring the Absorption Coefficient of Pure Water in the UV With an Integrating Cavity Absorption Meter

Conference Proceedings for Ocean Optics XXI

Ring-Down Absorption Spectroscopy in an Integrating Cavity

Conference Proceedings for Frontiers in Optics/Laser Science

Optical Society of America (OSA)

Vice President, Texas A&M Student Chapter (2009-2011)

Optical Society of America (OSA)

Vice President, Texas A&M Student Chapter (2009-2011)

Optical Society of America (OSA)

Vice President, Texas A&M Student Chapter (2009-2011)

Optical Society of America (OSA)

Vice President, Texas A&M Student Chapter (2009-2011)

Optical Society of America (OSA)

Vice President, Texas A&M Student Chapter (2009-2011)

Optical Society of America (OSA)

Vice President, Texas A&M Student Chapter (2009-2011)

Optical Society of America (OSA)

Vice President, Texas A&M Student Chapter (2009-2011)

Optical Society of America (OSA)

Vice President, Texas A&M Student Chapter (2009-2011)

Optical Society of America (OSA)

Vice President, Texas A&M Student Chapter (2009-2011)

Optical Society of America (OSA)

Vice President, Texas A&M Student Chapter (2009-2011)

Optical Society of America (OSA)

Vice President, Texas A&M Student Chapter (2009-2011)

Optical Society of America (OSA)

Vice President, Texas A&M Student Chapter (2009-2011)

Optical Society of America (OSA)

Vice President, Texas A&M Student Chapter (2009-2011)