Dr Nadir Hossain
Research Fellow
Email: nadir.hossain@surrey.ac.uk
Phone: Work: 01483 68 9403
Room no: 08 ATI 02
Further information
Biography
Nadir was born in Shariatpur, Bangladesh. He holds an M.Eng.Sc (by research) in Optical Communication from Multimedia University, Malaysia as well as B. Sc. (Hons) in Engineering in Computer Science & Engineering from Khulna University, Bangladesh. Nadir was awarded UniS fully funded PhD studentship. Currently he is working as a fully funded PhD research student in photonics group at the Advanced Technology Institute, University of Surrey. Recently he is awarded Royal Academy of Engineering Student Development Fellowship 2009.
Research Interests
Nadir's current area of research is semiconductor laser physics particularly modeling, optimization and experimental evaluation of dilute nitride laser for optical computer. Of key importance to the future of communications and computer technology is the convergence of photonics and electronics. One of the most interesting future applications for lasers is as on-board light sources for fast processing and data transfer within computers. Silicon CMOS technology dominates computer processors; however, its indirect band gap makes it unsuitable for producing lasers. The objective of Nadir's current research is to develop semiconductor lasers made from a new class of direct band gap “dilute” nitride materials, in particular GaNAsP which can uniquely be grown monolithically on silicon. Working closely with partners in Marburg University, Germany, he will identify the fundamental processes governing the performance of these lasers and use this to develop optimised devices for high temperature operation (important for computer applications). The successful outcome of this research will be to have increased the understanding of this new semiconductor system, and to have used it to produce fully operational silicon based lasers.
Nadir's others research area includes hybrid fiber / doped fiber amplifiers (DP R-EDFA / DRA, TDFA) and fiber based optical sensor for bio-photonic application.
Publications
Journal articles
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(2012) 'Temperature and Bi-concentration dependence of the bandgap and spin-orbit splitting in InGaBiAs/InP semiconductors for mid-infrared applications'. Applied Physics Letters, 101 (22)doi: 10.1063/1.4768532Full text is available at: http://epubs.surrey.ac.uk/745673/
Abstract
Replacing small amounts of As with Bi in InGaBiAs/InP induces large decreases and increases in the bandgap, E, and spin-orbit splitting, Δ, respectively. The possibility of achieving Δ > E and a reduced temperature (T) dependence for E are significant for suppressing recombination losses and improving performance in mid-infrared photonic devices. We measure E (x, T) and Δ (x, T) in InGa BiAs/InP samples for 0 x 0.039 by various complementary optical spectroscopic techniques. While we find no clear evidence of a decreased dE/dT (≈0.34 ± 0.06 meV/K in all samples) we find Δ > E for x > 3.3-4.3. The predictions of a valence band anti-crossing model agree well with the measurements. © 2012 American Institute of Physics.
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(2012) 'Efficiency-limiting processes in Ga(NAsP)/GaP quantum well lasers'. Applied Physics Letters, 101 (1)doi: 10.1063/1.4733312Full text is available at: http://epubs.surrey.ac.uk/729744/
Abstract
We report on the carrier recombination mechanisms in dilute nitride Ga(NAsP)/GaP quantum well lasers. Spontaneous emission measurements show that defect-related recombination in the devices is less significant compared with other GaAs-based dilute nitride lasers. From temperature dependent measurements, we find that the threshold current density, J is dominated by non-radiative recombination process(es), which account for at least 91 of J at room temperature. The characteristic temperature, T (T ) is measured to be ∼104 K (∼99 K) around 200 K, which drops to ∼58 K ( ∼37 K) around room temperature. Hydrostatic pressure measurements reveal a strong increase of threshold current with increasing pressure. This implies that current leakage dominates carrier recombination which is also responsible for their low T and T values at room temperature. © 2012 American Institute of Physics.
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(2012) 'Recombination mechanisms and band alignment of GaAs1-xBix/GaAs light emitting diodes'. APPLIED PHYSICS LETTERS, 100 (5) Article number ARTN 051105 doi: 10.1063/1.3681139Full text is available at: http://epubs.surrey.ac.uk/531960/
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(2011) 'Laser operation of Ga(NAsP) lattice-matched to (001) silicon substrate'. AMER INST PHYSICS APPLIED PHYSICS LETTERS, 99 (7) Article number ARTN 071109 doi: 10.1063/1.3624927Full text is available at: http://epubs.surrey.ac.uk/7888/
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(2011) 'Reduced threshold current dilute nitride Ga(NAsP)/GaP quantum well lasers grown by MOVPE'. INST ENGINEERING TECHNOLOGY-IET ELECTRONICS LETTERS, 47 (16), pp. 931-933.doi: 10.1049/el.2011.1927
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(2011) 'Band structure properties of novel BxGa1-xP alloys for silicon integration'. AMER INST PHYSICS JOURNAL OF APPLIED PHYSICS, 110 (6) Article number ARTN 063101 doi: 10.1063/1.3630018Full text is available at: http://epubs.surrey.ac.uk/7895/
Conference papers
- . (2012) 'InGaBiAs/InP semiconductors for mid-infrared applications: Dependence of bandgap and spin-orbit splitting on temperature and bismuth content'. ICP 2012 - 3rd International Conference on Photonics 2012, Proceedings, , pp. 154-158.
- . (2011) 'Physical properties of monolithically integrated Ga(NAsP)/(BGa)P QW lasers on silicon'. IEEE 8th IEEE International Conference on Group IV Photonics, London, UK: Group IV Photonics, pp. 148-150.
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(2010) 'Recombination and loss mechanisms in GaNAsP/GaP QW lasers'. Proceedings of Photonics Global Conference, Orchard, Singapore: PGC 2010Full text is available at: http://epubs.surrey.ac.uk/733517/
Abstract
In this paper the authors present a comprehensive study of the threshold current and its temperature dependence in novel direct band-gap Ga(NAsP)/GaP QW lasers which provide a potential route to lattice matched monolithic integration of long term stable semiconductor lasers on silicon. It is found that near room temperature, the threshold current is dominated by nonradiative recombination accounting for ~87% of the total threshold current density. A strong increase in threshold current with hydrostatic pressure implies that a carrier leakage path is the dominant carrier recombination mechanism.
- . (2010) 'Physical properties of Ga(NAsP)/GaP QW lasers grown by MOVPE'. IEEE 23rd Annual Meeting of the IEEE Photonics Society, Denver, USA: Photonics 2010, pp. 65-66.
- . (2010) 'Lasing properties of monolithically integrated Ga(NAsP)/(BGa)P QW lasers on a Silicon substrate grown by MOVPE'. 22nd IEEE International Semiconductor Laser Conference, Kyoto, Japan: 22nd IEEE ISLC, pp. 109-110.
- . (2010) 'Role of growth temperature on the physical characteristics of GaAsSb/GaAs QW lasers'. IEEE 23rd Annual Meeting of the IEEE Photonics Society, Denver, USA: Photonics 2010, pp. 59-60.
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(2010) 'Influence of device structures on carrier recombination in GaAsSb/GaAs QW lasers'. Proceedings of Photonics Global Conference, Orchard, Singapore: PGC 2010Full text is available at: http://epubs.surrey.ac.uk/733523/
Abstract
We investigate the temperature and pressure dependence of carrier recombination processes occurring in various GaAsSb/GaAs QW laser structures grown under similar growth conditions. Thermally activated carrier leakage via defects is found to be very sensitive to the strain induced interface imperfections. Nonradiative recombination is found to be sensitive to the number of QWs. A strain compensated MQW structure leads to a reduced contribution of non-radiative recombination to the threshold current density (Jth) and a high characteristic temperature (T0) of 73K at room temperature.
- . (2010) 'MOVPE growth and characterization of Ga(NAsP) laser structures monolithically integrated on Si (001) substrates'. 22nd IEEE International Semiconductor Laser Conference, Kyoto, Japan: 22nd IEEE ISLC, pp. 143-144.
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(2010) 'Improved performance of GaAsSb/GaAs SQW lasers'. Proceedings of SPIE: Materials + Mode-Locking, San Francisco, USA: Novel In-Plane Semiconductor Lasers IX 7616doi: 10.1117/12.842253Full text is available at: http://epubs.surrey.ac.uk/733522/
Abstract
This paper reports the improvements and limitations of MBE grown 1.3μm GaAsSb/GaAs single QW lasers. At room temperature, the devices show a low threshold current density (Jth) of 253 Acm-2, a transparent current density of 98 Acm-2, an internal quantum efficiency of 71%, an optical loss of 18 cm-1 and a characteristic temperature (T0) = 51K. The defect related recombination in these devices is negligible and the primary non-radiative current path has a stronger dependence on the carrier density than the radiative current contributing to ~84% of the threshold current at RT. From high hydrostatic pressure dependent measurements, a slight decrease followed by the strong increase in threshold current with pressure is observed, suggesting that the device performance is limited to both Auger recombination and carrier leakage.
Teaching
Demonstrating Electronics (Theory) Level - 1.
Projects
Modeling, Optimization and Experimental Evaluation of Hybrid DP EDFA/DRA for Long Haul OFCS
Project Achievements:
1. Theoretical modeling and experimental demonstration of single pass (SP) and double-pass (DP) EDFA. (Considering both local pump and remote pump power).
2. Theoretical modeling and experimental demonstration of Distributed Raman Amplifier (DRA) for long haul OFCS.
3. Modeling of 2.5 Gbit/s long haul OFCS using hybrid DP R-EDFA and DRA.
4. Optimum pumping scheme.
5. Optimum R-EDFAs locations in transmission system.
In-situ Multiple Parameter Monitoring and Measurement System for Liquid Hydrocarbon using Fiber Opti
Project Goals:
1. To model fiber gratings and analyze the effect of external perturbations such as temperature and index on the dispersion characteristics and propagation modes of the fiber.
2. To design novel fiber grating configurations to improve their sensitivity and stability toward external perturbations, i.e. index and temperature, and capable of multiple parameter sensing function.
3. To construct the fiber optic sensor and to experimentally characterize the sensor’s performance towards index and temperature changes.
4. To integrate several sensor elements, construct and characterize the multiplexed in-situ monitoring system.
