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Zeeshan Ahmed (Fed)

A spectroscopist by training, Zeeshan Ahmed joined the Thermodynamic Metrology Group at NIST in 2012. His research activities focus on the development of novel, disruptive technologies that aim to replace legacy-based measurement platforms. Specifically, his current research is focused on the development of physics-constrained machine learning models for photonic sensors. This line of inquiry seeks to enable a cost-effective, integrated multi-functional photonic sensor package with intelligent-calibration capabilities.

Zeeshan Ahmed was awarded the Bronze medal for superior service in 2016 and the Equal Employment Opportunity Award in 2015 for his work with socio-economically disadvantaged students. He currently serves as the Chairman of Task group on Emerging Technologies under Contact Thermometry at the BIPM. In addition, he holds an Affiliate Faculty position with George Mason University’s Chemistry department and the Quantum Science and Engineering Center (QSEC) where he collaborates with fellow members on the development of disposable, embedded sensor networks for tissue engineering applications.


    Research Projects


    • 2016 Bronze Medal for Superior Federal Service
    • 2016 STAM Altmetrics Award
    • 2015 Equal Employment Opportunity/Diversity Award
    • 2009 National Research Council Postdoctoral Research Associateship



    Ryan P. Fitzgerald, Zeeshan Ahmed, Denis E. Bergeron, Nikolai Klimov, Dan Schmidt, Ronald Tosh
    With the recent redefinition of the SI base units in terms of constants of nature, the race is on to maximize achievable precision by developing primary

    On-chip Silicon Photonics Radiation Sensors

    Nikolai N. Klimov, Zeeshan Ahmed, Lonnie T. Cumberland, Ileana M. Pazos, Ronald E. Tosh, Ryan P. Fitzgerald
    We have examined the impact of cobalt-60-ray radiation up to 1 megagray (MGy) absorbed dose on silicon photonic devices. We do not find any systematic impact


    Patent Images and description for 10,955,617

    High-Resolution Photonic Thermometer Article

    NIST Inventors
    Kevin O Douglass , Zeeshan Ahmed and Nikolai Klimov
    Patent Description NIST has created a method that sense temperature variations on a µK-level using an on-chip integrated passive photonic device that features a high-quality factor nanocavity. The method includes the (i) improved design of nanobeam photonic crystal cavity, (ii) specialized fiber­

    Deformometer for Determining Deformation of an Optical Cavity Optic

    NIST Inventors
    Zeeshan Ahmed , Kevin O Douglass , Stephen Eckel , Patrick Egan and Jay H. Hendricks
    Patent Description NIST has developed a device that uses multiple wavelengths (colors) of light and/or multiple species of gas to independently measure the distortions imposed on an optical cavity, cell, or other optical element that holds gas due to the forces applied by the gas. The device

    Photonic Calorimeter and Process for Performing Calorimetry

    NIST Inventors
    Ronald Tosh , Zeeshan Ahmed , Ryan P. Fitzgerald and Nikolai Klimov
    Patent Description The invention i s a photonic device whose resonance characteristics (such as, quality factor, peak position, and free spectral range) change in a predictable way in response to the interaction of radiation with the sensor and/or its surroundings. The invention can be used in an
    A list of radiation-induced materials modifications that are NIST traceable

    Photonic Dosimeter and Process for Performing Dosimetry

    NIST Inventors
    Ronald Tosh , Zeeshan Ahmed , Ryan P. Fitzgerald and Nikolai Klimov
    Patent Description Radiation-induced materials modification is ubiquitous. These applications rely on dosimetry to reliably deliver the desired amount of radiation to the right place. Currently the dosimetry standard is based on calorimetry of a large water phantom irradiated exclusively by Co-60
    Photonic thermometer packages

    Optical Temperature Sensor

    NIST Inventors
    Zeeshan Ahmed , Stephen Semancik , Jacob Taylor and Gregory F. Strouse
    The photonic temperature sensor relies on ultra-sensitive, frequency-based measurements of the effect of heat on the dimensions and predominant thermo-optic properties of the photonic resonator.
    Created May 31, 2018, Updated June 15, 2021