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Search Publications by: Zeeshan Ahmed (Fed)

Displaying 76 - 95 of 95

Fabry-Perrot cavity-based silicon photonic thermometers with ultra-small footprint and high-sensitivity

July 1, 2015

Author(s)

Nikolai N. Klimov, Thomas P. Purdy, Zeeshan Ahmed

In this work we report on the development of silicon photonic temperature sensors with ultra-small foot print and high temperature sensitivity as an alternative solution to legacy-based resistance thermometers.

Fabrication and Characterization of On-Chip Integrated Silicon Photonic Bragg Grating and Photonic Crystal Cavity Thermometers

June 30, 2015

Author(s)

Nikolai Klimov, Thomas P. Purdy, Zeeshan Ahmed

We report on the fabrication and characterization of photonic-based nanothermometers, a silicon photonic Bragg grating and photonic crystal cavity. When cladded with silicon dioxide layer the sensors have at least eight times better sensitivity compared to

Fiber Bragg Gratings Embedded in 3D-Printed Scaffolds

June 1, 2015

Author(s)

Peter Liacouras, Khazar Choudhry, Grant Grant, Gregory F. Strouse, Zeeshan Ahmed

In recent years there has been considerable interest in utilizing fiber optic based sensors as embedded sensor for fabricating smart materials. One of the primary motivations is to provide real-time information on the structural health of the material so

Systematic Examination of Ring Resonator Structures for Temerpature Sensing Applications

June 1, 2015

Author(s)

Nikolai N. Klimov, Zeeshan Ahmed

In recent years silicon photonic devices have emerged as a powerful tool for devleop novel, sensitivity sensors. In a recent study we systematically examined the impact of structural parameters on silicon ring resonators performance. In this study, we

On-Chip Silicon Photonic Thermometers: from Waveguide Bragg Grating to Ring Resonators sensors

May 13, 2015

Author(s)

Nikolai Klimov, Thomas P. Purdy, Zeeshan Ahmed

Fundamental limitations of resistance thermometry, as well as the desire to reduce sensor ownership cost has led to considerable interest in the development of photonic temperature sensors as an alternative to resistance thermometers. These innovative

Nurturing a Disruptive Technology for Thermodynamic Metrology

September 12, 2014

Author(s)

Zeeshan Ahmed

This presenation lays out a case, based on economic and technologic considerations, that the present technologies for temperature and pressure measurement are ripe for disruption. We argue that a better use of research funds is to identify and nuture

TRANSITIONING FROM RESISTANCE DEVICES TO PHOTONIC DEVICES FOR TEMPERATURE MEASUREMENTS

September 12, 2014

Author(s)

Zeeshan Ahmed, Gregory F. Strouse

For the past century, industrial temperature measurements have relied on resistance measurement of a thin metal wire or filament whose resistance varies with temperature. Though resistance thermometers can routinely measure industrial temperatures with

Ultra-Sensitive Chip-Based Photonic Temperature Sensor Using Ring Resonator Structures

February 3, 2014

Author(s)

Haitan Xu, Mohammad Hafezi, Jingyun Fan, Jacob Taylor, Gregory F. Strouse, Zeeshan Ahmed

Temperature is one of the most measured quantity in the world, second only to time. Recently there has been considerable interest in developing photonic temperature sensors to leverage advancements in frequency metrology. Here we show that Silicon based

State Resolved THz Spectroscopy and Dynamics of Crystalline Peptide/Water Systems

July 11, 2011

Author(s)

Zeeshan Ahmed, Shin G. Chou, Karen M. Siegrist, David F. Plusquellic

State resolved THz studies of crystalline peptides and their hydrates have provided precise measures of the infrared active phonon modes that reflect motions on the longest possible length scales in these systems. The impact of co-crystallized water on the

Far Infrared Characterization of Single and Double Walled Carbon Nanotubes

January 17, 2011

Author(s)

Shin G. Chou, Zeeshan Ahmed, Georgy Samsonidze, Jing Kong, Mildred Dresselhaus

Variable temperature high resolution far infrared absorption measurements were carried out for single walled carbon nanotubes samples with different diameter distributions. At a temperature where kBT is significantly lower than the phonon energy, the broad