A synthesis is made of the optical model for a quantum well (QW) and a quantum dot (QD) laser using Fermi golden rule and the electrical model based on continuity equation for a Transistor Laser. The calculated values of threshold base current and light power for InGaAs QW embedded in GaAs base agree with the experimental value. The predicted threshold base current for Quantum Dots is an order of magnitude lower. © 2011 IEEE.

BRATATI MUKHOPADHYAY

Radio Physics and Electronics

R BASU

P K BASU

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Unified model for electrical and optical characteristics of a Transistor Laser with InGaAs quantum well and dot in GaAs base

2011 30th URSI General Assembly and Scientific Symposium, URSIGASS 2011

We have developed the theory for the threshold base current, light power output and small signal modulation response of a transistor laser, the base of which contains a quantum well (QW) with a layer of quantum dots (QDs) inserted within it. Our theory involves the solution of the continuity equation for an arbitrary location of the QW in the base, and the solution of coupled rate equations for carriers and photons in the QD. The excitonic recombination model is assumed to be valid in the QD. The estimated threshold base current for InAs QDs embedded in the InGaAs QW is found to be smaller than the value for the InGaAs QW in the GaAs base. The values of the modulation bandwidths for different values of the base current however do not reach the high values obtained for the QW system. © 2012 IOP Publishing Ltd.

Semiconductor Science and Technology

Analytical theory of a small signal modulation response of a transistor laser with dots-in-well in the base

We have solved the continuity equation for electrons in the base of an InGaP-GaAs-GaAs heterojunction bipolar transistor laser (TL) in which the position of an InGaAs quantum well (QW) in GaAs base is variable. The injected minority carrier is related to the two-dimensional carrier in QW via virtual states (VSs). The values for optical gain in the QW are obtained by considering subband energies and envelope functions in presence of strain, polarization dependent momentum matrix element and Lorentzian lineshape. Relating the gain with threshold current and the latter with base current via VS current, the threshold base current and power output from the TL are estimated. Good agreement between the calculated and the experimental threshold base currents is obtained and the match for light output power is satisfactory within experimental uncertainty. Our calculated charge distribution in the base shows similar behaviour as in the charge control analysis of the experimental data. © 2011 IOP Publishing Ltd.

Journal	2011 30th URSI General Assembly and Scientific Symposium, URSIGASS 2011
Publisher	-
Open Access	No