Articles written in Bulletin of Materials Science

    • Effect of optical parameters on design of highly reflecting distributed Bragg reflectors based on compound semiconductors for space applications


      More Details Abstract Fulltext PDF

      Comprehensive model for the design of highly reflecting distributed Bragg reflectors (DBRs) is investigated for spectral band, ranging from ultraviolet to short wavelength infrared (SWIR). The reflectivity calculation is done using thin film multiple reflection technique. The variation of reflectivity as a function of wavelength, number of grown epilayers, angle of incidence and difference between refractive indices of constituent epilayers is examined. The target wavelengths for reflectivity simulation include 1.55 and 1.3 $\mu$m for optical communication, 850 and 980 nm for infrared (IR) imaging devices and chip-scale atomic clocks, and 412 and 443 nm for UV light emitting diodes and antireflection coatings for charge-coupled devices and solar cells. The reflectivity values calculated for compound semiconductor DBRs lie between 95 and 99%. It is also inferred that the reflectivity of grown epilayers and broadness of operational spectrum increases with number of epilayers. If DBR stack is grown on lattice mismatched substrate, increment of the reflectivity is found only at single wavelength. As the angle of incidence increases from 0$^{\circ}$to80$^{\circ}$,blue shift in reflectance (towards low wavelength) is also observed. The increase in reflectivity is also observed with increase in difference in refractive indices of epilayers.

  • Bulletin of Materials Science | News

    • Dr Shanti Swarup Bhatnagar for Science and Technology

      Posted on October 12, 2020

      Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
      Chemical Sciences 2020

      Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
      Physical Sciences 2020

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2021-2022 Indian Academy of Sciences, Bengaluru.