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Photonics Research of Bio/Nano Environments

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Professor Toussaint was a speaker at The National Academies of Sciences, Engineering, and Medicines Committee on the Use of Race and Ethnicity in Biomedical Research

This was the third meeting of the Committee on the Use of Race and Ethnicity in Biomedical Research. The committee held a public workshop with invited speakers to explore different research contexts in which race and ethnicity arise and new research approaches and alternatives to using race and ethnicity categories.

Professor Toussaint was a featured Speaker presenting on Understanding the  Challenges in Developing an Equitable Pulse Oximeter.  Watch the meeting here. His talk starts at the 47:15 min mark

Professor Toussaint is Lead Author for the Optics Express Special Feature: “Amplify Black Voices in Optics and Photonics”

The significant underrepresentation of Blacks in optics and photonics with respect to authors, invited speakers, conference chairs, reviewers, associate editors and editors in chiefs of Optica’s journals demands special attention. In accordance with the Optica June 2020 Commitment to Change and independent statements from the Optica Leadership and the 2016-2020 Optica Ambassadors, a special feature issue to amplify Black voices in optics and photonics was proposed. While, by no means, is this a solution, it is a step in the direction of inclusivity to elevate the visibility of the researchers (and their work) belonging to our optics community.

Through this special issue we highlight the excellent and exciting research in optics and photonics led by some of the Black researchers in the field. It is our intention that this special feature will bring awareness to the research contributions from this community for both present and future optics researchers from all walks of life. Thus, with this special issue, we take a snapshot of this community with 13 selected papers across 5 Optica Publishing Group journals (Applied Optics, Biomedical Optics ExpressOptics ExpressOptics Letters, and Optica). A companion piece to this special feature was published in a May 2023 Optics and Photonics News feature Breaking Barriers, Advancing Optics [1].

The topics covered in this special feature represent a diverse range of research areas that include metasurfaces, fiber optic biomedical sensors, photoacoustics, optoelectronics, space-time optics, computational optics, and silicon photonics. To facilitate reading through the special feature, we have binned these topics into three broad categories: bioimaging and biosensing, on-chip photonics and optimization in photonic systems, and entangled photons and applications of structured light.

Read more here

Jillian’s Work on Two-Photon Polymerization was Accepted by Optics Express

Two-photon polymerization (TPP) is an advanced 3D fabrication technique capable of creating features with submicron precision. A primary challenge in TPP lies in the facile and accurate characterization of fabrication quality, particularly for structures possessing complex internal features. In this study, we introduce an automated brightfield layerwise evaluation technique that enables a simple-to-implement approach for in situ monitoring and quality assessment of TPP-fabricated structures. Our approach relies on sequentially acquired brightfield images during the TPP writing process and using background subtraction and image processing to extract layered spatial features. We experimentally validate our method by printing a fibrous tissue scaffold and successfully achieve an overall system-adjusted fidelity of 87.5% in situ. Our method is readily adaptable in most TPP systems and can potentially facilitate high-quality TPP manufacturing of sophisticated microstructures. Read more here

Krishangi Krishna’s poster took second place at Boston Photonics Day

Traditional optical tweezers rely on the use of continuous-wave laser sources with moderate to high optical powers, leading to unwanted thermal effects. Here, we demonstrate that a femtosecond laser can provide optical tweezing of microparticles using an average power as low as 80 uW. 

Our work on Interferometry was published in Optica

When using the Space-Time light sheet, the interferometer exhibits 23% higher phase stability compared to the Gaussian light sheet (GLS), and 80% higher stability when compared to the Gaussian beam (GB). We find that while both ST light sheet and GLS exhibit significantly higher phase stability than the GB, ST light sheets have the added advantage of being resistant to speckle generation when a thin diffuser is inserted in the interferometer. Additionally, we show that interferometry using the ST light sheet results in approximately 11× more accurate measure of an oxide thickness on the substrate than the Gaussian beam. Our findings provide a simple approach to improving the stability of optical interferometry for applications, such as high-precision length measurements, enhanced sensing, and quantum optical experiments

Read more here

Our TPL real-time monitoring work is featured on Optica’s front page

Jillian Sun’s work presents a new way to monitor two-photon lithography nanoscale fabrication could help improve the accuracy and efficiency of creating 3D engineered tissue scaffolds, according to a new study. Tissue scaffolds mimic the natural extracellular matrices found in the body, which creates a 3D environment ideal for tissue formation.

The article can be found here

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Our optical coherence conversion work was highlighted in the Editor’s Pick collection in Journal of Optics!

Our recent tutorial on reversible optical coherence conversion was highlighted in the Editor’s Pick collection in Journal of Optics!

This work introduces the concept and experimentation of reversible optical coherence conversion, and outlines optical coherency matrix tomography as a method for measuring the full coherence of a field. To date, coherence conversion has only been demonstrated between the spatial and polarization degrees-of-freedom (DoFs). Coherence conversion offers a new control over an optical field’s DoFs—protecting against deleterious scrambling effects.Figure 3.

To read more, click here.

Our work on pulse oximeter was spotlighted by National Public Radio

The NPR news reported our work in pulse oximeter and the article together with an audio could be found here: ‘When it comes to darker skin, pulse oximeters fall short‘. The article showed our opinion that the commercial devices have been shown in research to produce inaccurate results in dark-skinned people, and our lab is developing technology that would be more accurate, regardless of skin tone.

Our pulse oximeter work got reported by Boston Globe

Our pulse oximetry work that aims to take racial bias out of oxygen readings by using a single wavelength of light that bypasses the skin is reported by Boston Globe, titled ‘A blood-oxygen detector without racial bias‘. Having completed preliminary testing, we intend to start clinical trials in a couple of months to confirm that their prototype eliminates skin-color bias.

A prototype of the pulse oximeter

Professor Toussaint organized the second in a series of Home Health Technologies in 2032 meetings to conceptualize equitable health tech of future

An interdisciplinary group of experts came together at Brown University for the second in a series of Home Health Technologies in 2032 meetings, namely Workshop 2: Healthcare Technologies in the Living Environment, to explore how emerging technologies might better support improved health and well-being without ever leaving home. Over the course of a day and a half in early June, working groups made of up varying stakeholders identified how in-home tech could drive paradigm shifts in healthcare, paying particular attention to solutions that would reduce the load on healthcare systems, address accessibility and equity for all populations and could realistically be translated into the home itself within ten years.

For more details about the event, please visit: https://engineering.brown.edu/news/2022-06-14/hht-32-part-2

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