Title: Decoupling the information encoded in wavevector and phase of light at nanoscale: Nanothermometry and more Nanothermometry and more

Speaker: Dr. Adarsh Vasista, ETH, Zurich

Abstract: Intensity, polarization, wavevector, and phase of light are often called the ‘golden quartet’ as measuring them provides all the information that characterizesthelight beam. Of the four, intensity and polarization are comparatively easy to measure. However, advanced microscopy techniques and elaborate analyses is required to accurately measure phase and wavevector, particularly at nanoscale.

In the first half of the talk, I will focus on the advantages and limitations of Fourier microscopy as a tool to measure the information encoded in wavevector of molecular emission. I will also elucidate the various applications of Fourier microscopy in remote sensing, angular momentum sensing etc [1,2].

In the next half of the talk, I will focus on how information encoded in optical phase can be used to accurately measure temperature in 3D at nanoscale, using optical diffraction tomography (ODT). I will also touch upon the limitations of the tomography technique particularly in its application as a nanothermometer [3].

References:

[1] A B Vasista et.al., Encyclopedia of Applied Physics,Wiley-VCH Verlag GmbH & Co. KGaA (Ed.).https://doi.org/10.1002/3527600434.eap817(2019)

[2] A B Vasista et. al., Nano Lett.,18,650–655(2018)

[3] A B Vasista et. al., Manuscript submitted(2022)