The amount of data traffic on optical networks is continuously increasing. In the transport core,

Key Success Factors:

To learn

To instal l

To use

To maintain

To manage

Vol. 4 Number 8 October 2015

Arti

cle

Newsletter

newsletter@fiberoptika.com

Paradigm shift from Electronics Domain to Optical Domain Device Development

Issue 4: Electronic Transistor to Optical Transistor

The transistor (trans + resistor i.e. transfer of current from low resistance to high resistance e.g. BJT) size has been projected to 5 nm (commercially) by

2020 (3 nm transistor was already developed in laboratory in year 2006 using FinFET technology,) which was invented in 1947 [1]. Electronic transistor

has been kept ruling from elementary stage since 1947 to modern electronic devices till date, however, in search of photonic ICs and optical computing,

developing optical transistor has been drawing attention of researchers to exploit the advantage of higher velocity of light (108 m/s) compared to drift

velocity of electron (105 m/s) for faster switching and computation [2]. Lesser power consumption is another attractive feature of optical transistor because

of absence of capacitance in connections among logic gates. There are several schemes reported in literature both at simulation and experimental

demonstration of optical transistors. Among them, few are (I): Soliton transistor [3], (ii): Micro ring resonator (MRR) and Cavity based optical transistor [4-

5], (iv): Cavity free system using Rydberg states [6],(vi) Excitons and exciton-polaritons based optical transistor[7-8], (vii): Photonic crystal and Raman

gain based [9], (viii): Nano-wire based optical transistors [10] etc. Various approaches have been adapted to model, fabricate and characterize the optical

transistors because an optimum optical transistor should be able to meet following criteria: (I): Cascadability, fan-out, logic level restoration, input/output

isolation, absence of critical biasing, logic level independent of loss [11]. Chen et al., [4] has reported a single gate photon (weak signal) based optical

transistor which can control source optical field signal consists of hundreds photons (strong signal). He has used a high fineness optical cavity with low

absorption and an optical quantum memory for later retrieval of atom.

The figure 1 shows the model of optical transistor using quantum electrodynamics (QED) cavity based on Electromagnetically Induces transparency (EIT)

in a four level system as reported by Chen et al. [4]. That system consists of optically trapped, ensemble of laser-cooled cesium atoms in a high-finesse

optical cavity functioning in strong interaction region of QED cavity. In that, one photon at gate blocks the resonator transmission. When control laser power

becomes zero, the weak gate signal is stored inside the atomic ensemble and it can be retrieved later by re-applying laser control beam without heat

References:[1]. J. Sander et al., “Room-temperature transistor based on a single carbon nanotube” available at: doi: 10.1038/29954[2]: J. Volz and A. Rauschenbeutel, “Triggering an Optical Transistor with One Photon”, DOI: 10.1126/science.1242905[3]: J. Bethge et al., “Solitonic Transistor in the Optical Event Horizon” doi:10.1364/CLEO_SI.2011.CMJ6[4]: W. Chen et al., “All-Optical Switch and Transistor Gated by One Stored Photon”, available at: 10.1126/science.1238169[5]: Q. Minghao et al., Optical Diodes and Transistors on a Silicon Chip “, DOI: 10.1364/FIO.2012.FW6C.6[6]: H. Gorniaczyk et al., “Single-Photon Transistor Mediated by Interstate Rydberg Interactions”, http://dx.doi.org/10.1103/PhysRevLett.113.053601[7]: Y. Y. Kuznetsova et al., “All-optical excitonic transistor”doi: 10.1364/OL.35.001587[8]: D. Ballarini et al., “All-optical polariton transistor “, doi: 10.1038/ncomms2734[9]: V. G. Arkhipkin and S. A. Myslivets,” All-optical transistor using a photonic-crystal cavity with an active Raman gain medium” http://dx.doi.org/10.1103/PhysRevA.88.033847[10]: B. Piccione et al., “All-optical active switching in individual semiconductor nanowires” doi:10.1038/nnano.2012.144[11]: D. A. B. Miller, “Are optical transistors the logical next step? “DOI:10.1038/nphoton.2009.240

Dr. Subhash C. Arya

Gate (free-space)

Mode

Source (Cavity)

Mode

Control beam

Dg

Ds

Fig. 1. Model of Optical Transistor [Ref. 4] Fig. 2. Optical Transistor’s function as

storage,switching and retrieval [Ref. 4]

Dear ReadersDear Readers

Wishing you all a joyful & Prosperous DussehraWishing you all a joyful & Prosperous Dussehra

Fiber Optika Technologies Pvt Ltd.Follow us on:

LIGHTSIM- Simulation Tool

Head Office#38, 22nd Main Road,14th CrossPadmanabhanagar, Bengaluru, Karnataka -560070E mail: info@fiberoptika.comWeb site: www.fiberoptika.comPh:- +91-80- 26395002, +91-80-26395003

Mumbai Office

1st Floor, Plot No. 31, Sector 19C, Vashi, Navi Mumbai, Maharashtra 400703, India

What’

s N

ew

LIG

HT

SIM

LIGHTSIM Simulations

The role of the optical transmitter is to convert an electrical input signal into the corresponding optical signal and then launch it into the optical fiber serving as a communication channel. The major component of optical transmitters is an optical source. Fiber-optic communication systems often use semiconductor optical sources such as Light-Emitting Diodes (LEDs) and semiconductor Lasers because of several inherent advantages offered by them.

Using our Light SIM simulation software PI characteristics of LED can be graphically studied by the plot of Output Power Vs Drive Current.

PI Characteristics of LED's

Phone:+91 22-27841425

LIGHT RUNNER IN DHAKA

Our Engineers were on tour to Dhaka to showcase current trends in optical communication and how LIGHT RUNNER helps in bridging academics and industry. As part of tour, series of demonstration in various Engineering colleges were carried out. Bangladesh University of Engineering and Technology, East West University, North South University and major Telecom Companies like Grameenphone(Telenor Group), Mango Teleservices Limited, Summit Group, Paradise Group of Industries and few other places were venues of events in Bangladesh.