Prof. Michael Rosenbluh, of the Department of Physics, is one of the founding directors of the Resnick Institute for Advanced Technology and a member of the Nano Photonics Center at the Institute of Nanotechnology and Advanced Materials (BINA).
Rosenbluh’s research is on the properties and uses of light and its interaction with matter in its various forms. His laboratory is involved in the use of ultra-short laser pulses to generate a high flux of correlated and entangled photon pairs.
They are also focused on the fabrication of metallic nanostructure arrays for enhancing Raman scattering and applying plasmonics for enhanced detection. Rosenbluh’s team uses coherent high frequency sidebands created on the output of a diode laser for making miniature atomic clocks, and makes optical waveguides that can be switched and modulated at very high speeds.
They also use chaotic optical sources for random bit generation, optical network communication applications and cryptography. Rosenbluh has also created new technologies which are potentially useful for efficiently harvesting the power of the sun.
In collaboration with industrial partners, Rosenbluh has developed a laser-based atomic clock that is ten times smaller than those currently available and requires a hundred times less power to operate. To improve clock accuracy, his team is working on an atomic beam based compact atomic clock.
Rosenbluh has also used nanofabrication techniques for making plasmonic nano-arrays, which have been shown to highly enhance surface Raman scattering. Such surface arrays may lead to the creation of more powerful tools for the identification of rare molecules.
In other applications of plasmonic structures, a novel detector based on a nano-well filled with semiconductor quantum dots and surrounded by a plasmonic lens focusing element has been demonstrated.
In the application of nanofabrication to optical waveguide structures in silicon, Rosenbluh, in collaboration with Prof. Valentine Freilikher of the Department of Physics, has been working on introducing random nanostructures into the waveguide which can be used to optically switch or modulate the waveguide transmission at extremely high speeds.
The scattering of coherent light by the nanostructures is also of great interest in fundamental studies of light localization in scattering media.
Rosenbluh and his team are also developing in fiber saturable absorbers, based on single walled carbon nanotubes, which can be used to mode-lock fiber lasers. The insertion of the carbon nanotubes in a fixed orientation is also expected to lead to controllable polarization properties. These can be useful in fiber polarization control of fiber lasers.
The generation of random bit sequences based on non-deterministic physical mechanisms is of paramount importance for cryptography and secure communications. High data rates require extremely fast generation rates which are the currently available technology cannot provide.
To resolve these problems, Rosenbluh, in conjunction with Prof. Ido Kanter, has developed an ultrafast random bit generator, based on a chaotic semiconductor laser, with time-delayed self-feedback. The generator, which holds the world record for generation rate, has additional interesting properties which can be applied to cryptography and secure optical communications amongst multiple users and networks.
Rosenbluh’s areas of interest include experimental studies in atomic and laser physics, electromagnetically induced transparency (EIT) and coherent population trapping, EIT atomic clocks, nonlinear optics – saturable absorption, optical properties of carbon nanotubes, four-wave mixing, light scattering, nanofabrication of optronic stuctures, correlated photon pair generation, optics based cryptography, and chaotic diode laser dynamics.