During 2nd year of my Ph.D.(2005-06) at JNCASR, I had the privilege of presenting a general seminar on ELECTROMAGNETICALLY INDUCED TRANSPARENCY. One of tricks I came across during the preparation of the talk was to modulate electronic transition of an atom or a molecule by intelligently choosing a pump and a probe laser beam. Based on the same principle, a letter in NATURE reports ‘A SINGLE MOLECULE OPTICAL TRANSISTOR’
1. Just as electrons in an electronic device can be modulated by transistor, photons radiated from a single dye molecule can be modulated (i.e., amplified or attenuated) using laser beams, which makes the whole system an optical transistor.
2. A pump laser beam (a pulsed laser) acts as gate and a probe beam (continuous wave laser) acts as the source.
3. By varying the power of the gate laser, the absorption and emission of light from a dye molecule can be modulated.
Following are some of the advantages of an optical transistor:
1. Photons are better candidates for long distance communication.
2. Unlike electronic signals, photonic signals do not perturb each other.
3. Coherence of photons can be maintained at a relatively higher temperature than electrons, which make them better candidates for quantum computation.
This recent report is indeed a breakthrough, and it is worth prusuing further research on the same lines. Ultimate goal can be an OPTICAL COMPUTER……
