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Photonic and Optomechanical Sensors for Nanoscaled and Quantum Thermometry

PhD & MSc Students

​PhD Students

 

Andrea Cupertino
​High Q-factor micromechanical membranes for intrinsically calibrated temperature sensors

Research Description: 

For a wide range of processes, from consumer electronics to space instrumentation, there is a growing need to make temperature measurements at smaller scales. The range of currently available thermometers, however, cannot meet the challenge. Nanotechnology now offers the possibility of innovative optomechanical sensors capable of measuring temperature on micrometre length scale. As heat can be viewed as the vibrating motion of atoms in a material, the newest technologies aim to measure temperature at the level of single quants of vibration (phonons). Not only could these new temperature sensors replace the standard high-accuracy platinum resistance thermometers, but embedded into production processes, many industrial users could benefit from this technology.

This PhD project will aim at engineering optomechanical sensors to create novel concepts for temperature sensors. The first requirement for reaching the high sensitivity needed for the envisioned measurements is to obtain high quality factors. Norte is pioneering in novel optomechanical platforms able to drastically reduce clamping and bending losses reaching a Quality Factor as high as 108. Within this PhD, these platforms will be exploited for sensing applications aiming at reducing the dependence on anchoring losses. To this end, phononic crystals have shown to be effective to further reduce the mechanical losses by strongly localizing acoustic waves. Building on this, the project will focus on studying and designing novel structures to employ these approaches for temperature sensing applications.         

Research lab: Department of Precision and Microsystems Engineering, Delft University of Technology
PhD period: March 2019 – March 2023
PhD supervisors: Richard Norte and Peter Steeneken (TU Delft)

 

Ferhat Loubar
​Quantum kelvin: an optomechanical measurement of temperature by quantum correlations and metrological validation

Abstract:

Temperature is probably the most important physical variable of state, influencing almost every physical, chemical, and biological process. Surprisingly, the world's most accurate temperature sensors rely on antiquated technologies that do not lend themselves to miniaturization, portability, or wide dissemination. In recent years, a wide variety of novel photonic thermometers have been proposed including photosensitive dyes, fiber Bragg gratings, and on-chip integrated silicon photonic nanostructures. Even more recently, the field of optomechanics, based on the reading of the mechanical motion of an object thanks to light, has emerged. Quantum optomechanics is now going into a new era by trying to develop new technologies based on / using high sensitive quantum measurements. At the forefront of these technologies, thermometry is one of the most obvious but also one of the most demanding.

The aim of the Internship/PhD is to demonstrate and validate an innovative primary temperature sensor using quantum technologies. The device under study is based on an optomechanical system combined with quantum measurements techniques that allow one to directly compare thermal fluctuations of a resonator with its quantum noise.         

​​Research labs: Laboratoire Kastler Brossel-Sorbonne Universités & LCM LNE Cnam
PhD period: October 2018 – September 2021
PhD supervisors: Tristan Briant (SU) & Stéphan Briaudeau (Cnam)

 

Lukas Weituschat
​Design of an opto-mechanical resonator for micro-scaled quantum thermometers
based in diamond

Abstract: 

A micro/nano photonic resonator will be developed using different material properties and device characteristics which depend on temperature (refractive index, physical dimensions) to measure the ambient temperature with high precision via light-matter interactions. To achieve this goal computer simulations of ring resonators based on silicon will be conducted using the simulation software COMSOL Multiphysics to compare their different behaviours in terms of sensitivity, robustness, etc. to present possibilities of temperature measurement (e.g. resistance thermometer, lead thermometer). The most promising devices will be fabricated in the facilities of the IMN-CSIC and an experimental setup to analyse the characteristics of fabricated devices will be established. Diamond will be investigated as a new material to exploit inherent optical and mechanical characteristics to achieve high optical and mechanical Q-factors. By simulating these devices with COMSOL Multiphysics the performance of the devices will be compared to the performance of the Si-based devices.

The possible implementation of photonic crystals into the micro-resonator will be investigated to explore its effect on temperature sensing and its use as a diamond-based optomechanical resonator.

Research lab: Instituto de Micro y Nanotecnología (CSIC)
PhD period: November 2018 – October 2021
PhD supervisors: Pablo-Aitor Postigo (IMN-CSIC)

   

Master's Students

 

Alberto Casas
​Design and fabrication of a setup for measuring photonic thermometers
at micro/nano scale with a stabilization of mK​.

Abstract:  

Metal based resistance thermometers are ubiquitously used for a wide range of application to measure temperature. Especially platinum based state-of-the-art thermometers are able to reach uncertainties below 10 mK. Recent approaches using photonic thermometers show great potential to reach comparable measurement uncertainties with the additional advantage of a metal free, chemical inert and mechanical robust sensor design. Furthermore, the working principles of photonic thermometers are mainly based on a determination of frequency changes of an optical resonance, which offer a potential relative uncertainty of 1·10–19.

CEM is currently involved in PhotOQuanT WP3 and WP4 in the metrological characterization of photonic devices and in the development of calibration procedures with traceability to the International Temperature Scale of 1990 (ITS-90) in the temperature range, at least, from 20 °C to 100 °C including uncertainties evaluation at the millikelvin level, if possible. In a first stage, the setup will be for free space light coupling measurement and the thermostat is a temperature controlled platform (using water from a high stability water bath). The temperature range is 10 °C to 80 °C and the best stabilities obtained are 4 mK at 20 °C and 30 mK at 60 °C.

Research lab: Centro Español de Metrología CEM (Spain)
Thesis period: June 2019 – June 2020 
Supervisors: Pablo-Aitor Postigo (IMN-CSIC), Dolores del Campo (CEM), Maria-Jose Martin (CEM)