Presentation is loading. Please wait.

Presentation is loading. Please wait.

Laser Group of Department of Physics Prof. HarshvardhanWanare Department Day, Golden Jubilee, IIT Kanpur, March 19-20, 2010 Prof. Asima Pradhan Prof. R.

Similar presentations


Presentation on theme: "Laser Group of Department of Physics Prof. HarshvardhanWanare Department Day, Golden Jubilee, IIT Kanpur, March 19-20, 2010 Prof. Asima Pradhan Prof. R."— Presentation transcript:

1 Laser Group of Department of Physics Prof. HarshvardhanWanare Department Day, Golden Jubilee, IIT Kanpur, March 19-20, 2010 Prof. Asima Pradhan Prof. R. Vijaya Prof. Raj K. Thareja Biophotonics Laser Plasma Interaction Quantum Optics Fiber Optics, Photonic Band Gap Materials

2

3

4

5

6 Recent publications 1.R.K. Thareja, A. Mohanta, D. Yadav and A. Kushwaha, (2010) Synthesis and Characterization of Nanoparticles and Nanocrystalline Functional Films, Materials Science Forum Vols. 636-637, 709-713. 2 A Mohanta and R. K. Thareja, (2009) Rayleigh scattering from gaseous phase nanoparticles synthesized by pulsed laser ablation of ZnO, J. Appl. Phys. 106, 124909. 3 Dheerendra Yadav, Varun Gupta, and Raj K Thareja (2009), Evolution and imaging of nanoparticles observed in laser ablated carbon plume, J Appl, Phys. 106, 064903. 4 Dheerendra Yadav, Varun Gupta, and Raj K Thareja, (2009) Ground state C 2 density measurement in carbon plume using Laser induced fluorescence spectroscopy, Spectra Chem ActaB 64, 986. 5 Archana Kushwaha, Antaryami Mohanta, Raj K Thareja, (2009) C 2 and CN dynamics and pulsed laser deposition of CN x films, J Appl. Phys. 105, 044902. 6 Archana Kushwaha and R K Thareja (2008) Dynamics of laser ablated carbon plasma: formation of C 2 and CN, Appl. Opt. 47, 65 7 A. Mohanta, V. Singh and Raj K Thareja (2008) Photoluminescence from ZnO nanoparticles in vapor phase, J. Appl. Phys. 104, 064903. 8 Antaryami Mohanta and Raj K Thareja (2008) Photoluminescence study of ZnO nanowires grown by thermal evaporation on pulsed laser deposited ZnO buffer layer, J. Appl. Phys. 104, 044906; Virtual J. Ultrafast Sc. 9. R. K. Thareja, A. K. Sharma, and S. Shukla (2008) Spectroscopic investigations of carious tooth decay, Med. Eng. & Phys. 30, 1143. 10. A Mohanta and R. K. Thareja, (2008) Photoluminescence study of ZnCdO alloy, J Appl Phys, 103, 024901.

7 Biophotonics:  Application of photonic science and technology to life sciences.  A rapidly emerging area of forefront, interdisciplinary research  Requires fundamental understanding of light-biomatter interaction Biophotonics:  Application of photonic science and technology to life sciences.  A rapidly emerging area of forefront, interdisciplinary research  Requires fundamental understanding of light-biomatter interaction For a reliable optical diagnostic tool:  Require combination of more than one technique  Fluorescence Spectroscopy and Imaging (Sensitive Technique)  Elastic Scattering (Structural Information)  Raman Spectroscopy (Specific in nature) For a reliable optical diagnostic tool:  Require combination of more than one technique  Fluorescence Spectroscopy and Imaging (Sensitive Technique)  Elastic Scattering (Structural Information)  Raman Spectroscopy (Specific in nature) Early detection of cancer : Spectroscopy and Imaging The basis of our research lies in extracting molecular (fluorescence, Raman) and subtle morphological (elastic scattering) characteristics of changes in human tissue during development of disease Early detection of cancer : Spectroscopy and Imaging The basis of our research lies in extracting molecular (fluorescence, Raman) and subtle morphological (elastic scattering) characteristics of changes in human tissue during development of disease Developed two techniques to extract authentic biochemical information from fluorescence spectra, which are modulated by wavelength dependent optical parameters

8 Methodology used by us for extraction of Intrinsic Fluorescence A. Polarized Fluorescence & polarized elastic scattering measurement based approach A purely experimental approach Normalization of polarized fluorescence by polarized elastic scattering spectra to remove the modulation of wavelength dependent optical transport parameters A. Polarized Fluorescence & polarized elastic scattering measurement based approach A purely experimental approach Normalization of polarized fluorescence by polarized elastic scattering spectra to remove the modulation of wavelength dependent optical transport parameters Optics Express, 2003, SPIE 2010. Fiber Jig B. Spatially resolved fluorescence measurement Hybrid diffusion theory, Monte Carlo based analytical model for spatially resolved fluorescence Determination of optical transport parameters at the excitation & emission wavelengths (morphology) Recovery of intrinsic fluorescence (biochemical) Depth information of inhomogeneity Applied Optics 2002,2006

9 IMueller imaging in human cervical tissues Emerging Stoke’s vector S 1 / S 2 / S 3 / S 4 / S 1 S 2 S 3 S 4 = Incident Stoke’s vector Mueller Matrix Emerging Stoke’s vector S S 2 / S 3 / S 4 / S 2 / S 3 / S 4 / Basal layer Microscope images Normal epithelium of cervix Dysplastic epithelium of cervix Normal epithelium of cervix Dysplastic epithelium of cervix 40µ40µ 40µ40µ Depolarization power images Fluorescence Imaging in tissues with handheld probe Polarized fluorescence spectra for normal & abnormal tissue through different fibers Average fluorescence spectra of normal & abnormal tissue NADH band area normalized by area of corresponding normal for co-polarized spectra/elastic scattering 0.22mm 7mm 4mm 2cm B C DEFGH 1mm Abnormal tissue Normal tissue Raman Spectroscopy in Human Tissue Polarized Raman Studies of Cervical Tissues PCA & Covariance Matrix Images PC2 Vs PC3 (Co-polarized) for cervical tissue PC2 Vs PC3 (Un-polarized) for cervical tissue Normal (1600 – 1700 cm -1 ) Cancerous (1600 – 1700 cm -1 ) Co-polarized Normal (1600 – 1700 cm - 1 ) Cancerous (1600 – 1700 cm -1 ) Normal (1300 – 1400 cm -1 )Cancerous (1300 – 1400 cm -1 ) Cross-polarized Co-Cross polarized

10 Future Plans Aim towards multimodal diagnostic tool Nano-based Imaging for contrast enhancement Recent Publications JOSA A, Vol.24, #6 (2007) Eng. Lett ( 2007) Nanotechnology 18 (2007) Journal of Biomedical Optics (2008) Optics Express, Vol. 17, 1600 (2009) Applied Optics, Vol. 48, 6099 (2009) IEEE JSTQE, in press, (2010) Current Ph.D students: 3 Current M.Tech students: 3 Funding: MCIT (DIT), CSIR

11 Multicolored Coherent Population Trapping Sub-harmonic comb with modulated fields New laser cooling mechanism, optical lattices, optical metrology Quantum Optics, Metamaterials and Imaging in Random media Input Output Input Non-linear dynamics All-optical bistability: double cavity, two-photon Negative-Positive Hysteresis Self-pulsing Quasi-periodic route to chaos

12 New paradigms of control in metamaterials with Dispersion All superluminal pulses become subluminal at larger propagation distances

13 Developing statistical methods of imaging in random media with diffuse light Modulated Source - ω 0o0o 180 o D1D1 D2D2 D3D3 D4D4 D5D5 Discovered fiber-based sensor that relies on tunneling of light

14 R. Vijaya Visiting Professor, IIT Kanpur (since Aug 2009) Permanent position: Professor, Department of Physics, IIT Bombay Sub-areas of research: (a)Nonlinear Fiber optics – experiment, computation, theory Objective: To build a multi-wavelength continuous wave / short-pulse source for fiber-optic communications b)Photonic band gap materials – experiment Objective: To build advanced functionalities such as directional emission and lowered threshold for lasing in self-assembled photonic crystals c)Integrated Optics - experiment Objective: Optimization of waveguide device fabrication in newer materials c)Computational Nonlinear Optics Objective: Calculation of non-linear optical coefficients of nano- clusters by DFT Present research funding > Rupees 1.0 Crore Present group: 3 Ph.D students, 1 Project staff, 1 Post-doctoral scientist

15 Research on Nonlinear Fiber Optics at IIT Bombay Research Lab established during 1999-2003 Major facilities: high-power fiber amplifier, time-domain (up to GHz) and frequency-domain (near-IR) measurement facilities, fiber splicer, several fiber-optic components such as isolators, circulators, couplers etc. and specialty fibers (EDF, DSF, HNLF) ■ Tunable fiber laser ■ Options for broadband (52 nm) and multi-wavelength (64 channels) output ■ Continuous wave and mode-lcked (15 ps and 10 GHz) output ■ Low pumping powers (< 200 mW) ■ C-band and L-band operations R (a) Erbium-doped fiber ring laser tunable from 1560 to 1605 nm by intra-cavity loss (b) Broadband generation using intra-cavity four-wave mixing in a low-dispersion fiber (c) Active mode-locking at 10 GHz - economical design based on Gunn oscillator (a)(b)(c)

16 Research on Photonic band gap materials at IIT Bombay Research Lab established during 2004-2007 Major facilities: Thin film spin coater, film thickness measurement system, lamp - monochromator - detector for 200nm to 2000 nm, pulsed Nd:YAG laser, waveguide coupling set-up and m-line set-up. ■ 3-D photonic crystals by self-assembly ■ characterization ■ Tuning of stop band ■ Inverse crystals ■ Photonic crystal heterostructures ■ Direction- dependent emission ■ Spectral narrowing ■ Photonic crystal waveguides Double stop bandDirectional emission Telecom bandLarge area crystal; Stop band at 550nmWaveguide by EBLLight guidance Self-assembled crystal

17 Future scope of studies Nonlinear dynamical effects in fiber lasers for Secure Communications Slow light characteristics in optical fibers Photonic crystal antenna – design issues Band-edge nonlinearities in Photonic crystals 1. J. Appl. Phys. 104, 053104 (2008) 2. Appl. Phys. A, 90, 559 (2008) 3. J. Non. Opt. Phys and Mater. 18, 85 (2009) 4. Applied Optics 48, G28 (2009) 5. Prog. Quant. Electr. (in press) Recent publications


Download ppt "Laser Group of Department of Physics Prof. HarshvardhanWanare Department Day, Golden Jubilee, IIT Kanpur, March 19-20, 2010 Prof. Asima Pradhan Prof. R."

Similar presentations


Ads by Google