Tayyab Imran
@eli-np.ro
Physicist/Laser System Department
ELI-NP
Laser Physicist
RESEARCH, TEACHING, or OTHER INTERESTS
Atomic and Molecular Physics, and Optics, Atomic and Molecular Physics, and Optics, Instrumentation
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
M. Hussain, G. O. Williams, T. Imran, and M. Fajardo
Informa UK Limited
The non-linear propagation of the intense near-infrared (NIR) driving field in crystals poses a challenge and can offer an opportunity to control the spectral properties of harmonics in solids. Here, we have investigated the non-linear propagation effects in wide bandgap dielectrics such as Magnesium Oxide (MgO), Chromium (Cr) doped MgO (Cr: MgO), Sapphire (Sa) crystals, and fused silica (FS). Furthermore, we have generated second and third harmonics (TH) and measured the linear polarization dependence of harmonics in these thin solids to explore the non-linear response at a strong field. We observe spectral shifts and broadening of the driving field spectrum which is imprinted on the harmonics. We attribute these effects to the strong photoionization, generation of free-carrier density, and self-phase modulation effects. This work shows the sensitivity to control the spectral profile of harmonics by manipulating the driving field, showing the possibility of new tailored solid-state ultraviolet sources for optical diagnostics.
Muddasir Naeem, Tayyab Imran, Mukhtar Hussain, and Arshad Saleem Bhatti
MDPI AG
A low-cost medium-power carbon dioxide (CO2) laser system is designed, constructed, and characterized to produce coherent, monochromatic laser radiation in the infrared region. The laser cavity is simulated and designed by using ZEMAX optic studio. A switch-mode high-tension pump source is designed and constructed using a flyback transformer and simulated using NI Multisim to study the voltage behavior at different node points. A prototype cooling system/chiller is designed and built using thermo-electric coolers (TEC) to remove the excess heat produced during laser action. Various parameters, such as pumping mechanism, chiller stability, efficiency, output power, and current at different applied voltages, are studied. The chiller efficiency at different output powers of the laser is analyzed, which clearly shows that the chiller’s cooling rate is good enough to compensate for the heat generated by the laser system. The center wavelength of the carbon dioxide laser is 10.6 μm with an FWHM of 1.2 nm simulated in the ZEMAX optic studio. The output beam penetration through salt rock (NaCl), wood, and acrylic sheet (PMMA) at various output powers is analyzed to measure the penetration depth rate of the CO2 laser.
Muddasir Naeem, Tayyab Imran, Mukhtar Hussain, and Arshad Saleem Bhatti
MDPI AG
Spectrometers have a wide range of applications ranging from optical to non-optical spectroscopy. The need for compact, portable, and user-friendly spectrometers has been a focus of attention from small laboratories to the industrial scale. Here, the Czerny Turner configuration-based optical spectrometer simulation design was carried out using ZEMAX OpticStudio. A compact and low-cost optical spectrometer in the visible range was developed by using diffraction grating as a dispersive element and a USB-type webcam CCD (charge-coupled device) as a detector instead of an expensive commercial diffraction grating and detector. Using National Instruments LabVIEW, data acquisition, processing, and display techniques were made possible. We employed different virtual images in LabVIEW programs to collect the pixel-to-pixel information and wavelength-intensity information from the image captured using the webcam CCD. Finally, we demonstrated that the OpticStudio-based spectrometer and experimental measurements with the developed spectrometer were in good agreement.
Muddasir Naeem, Noor-ul-ain Fatima, Mukhtar Hussain, Tayyab Imran, and Arshad Saleem Bhatti
MDPI AG
We report the design simulation of the Raman spectrometer using Zemax optical system design software. The design is based on the Czerny–Turner configuration, which includes an optical system consisting of an entrance slit, two concave mirrors, reflecting type diffraction grating and an image detector. The system’s modeling approach is suggested by introducing the corresponding relationship between detector pixels and wavelength, linear CCD receiving surface length and image surface dimension. The simulations were carried out using the POP (physical optics propagation) algorithm. Spot diagram, relative illumination, irradiance plot, modulation transfer function (MTF), geometric and encircled energy were simulated for designing the Raman spectrometer. The simulation results of the Raman spectrometer using a 527 nm wavelength laser as an excitation light source are presented. The present optical system was designed in sequential mode and a Raman spectrum was observed from 530 nm to 630 nm. The analysis shows that the system’s image efficiency was quite good, predicting that it could build an efficient and cost-effective Raman spectrometer for optical diagnostics.
M. Hussain, S. Kaassamani, T. Auguste, W. Boutu, D. Gauthier, M. Kholodtsova, J.-T. Gomes, L. Lavoute, D. Gaponov, N. Ducros,et al.
AIP Publishing
High harmonic generation (HHG) in crystals has revealed a wealth of perspectives such as all-optical mapping of the electronic band structure, ultrafast quantum information, and the creation of all-solid-state attosecond sources. Significant efforts have been made to understand the microscopic aspects of HHG in crystals, whereas the macroscopic effects, such as non-linear propagation of the driving pulse and its impact on the HHG process, are often overlooked. In this work, we study macroscopic effects by comparing two materials with distinct optical properties, silicon (Si) and zinc oxide (ZnO). By scanning the focal position of 85 fs duration and 2.123 μm wavelength pulses inside the crystals, (Z-scan) we reveal spectral shifts in the generated harmonics. We interpret the overall blueshift of the emitted harmonic spectrum as an imprint of the spectral modulation of the driving field on the high harmonics. This process is supported with numerical simulations. This study demonstrates that through manipulation of the fundamental driving field through non-linear propagation effects, precise control of the emitted HHG spectrum in solids can be realized. This method could offer a robust way to tailor HHG spectra for a range of applications.
Muddasir Naeem, Rabiya Munawar, Mukhtar Hussain, Tayyab Imran, and Arshad Saleem Bhatti
CMV Verlag
Blumlein discharge circuit stores electrical energy in its transmission line and canreleasethisenergy within a few nanoseconds. This leads the Blumlein to discharge circuit for many applications ranging from electrical discharge in the air to generate nitrogen laser, excitation source for vaporlasers to sub-nanosecond avalanche drivers.In this letter, we have simulated the equivalent Blumlein discharge circuitin Multisimulation and compared the results with the analytical modelto have the insight ofvariations of voltage, current and power in the Blumlein circuit. The Blumlein circuit isdivided into spark gap (spark gap)and Blumlein transmission linesections to observe the voltage, current and power oscillations.The rapid oscillations of voltage across the spark gap initiatethe discharge in the long transmission lines of Blumlein thatgenerates the coherent UV pulses.This study could pave the way towards the generation of ultraviolet (UV) pulses in the air at the atmospheric pressure.
Mukhtar Hussain, Hugo Pires, Willem Boutu, Dominik Franz, Rana Nicolas, Tayyab Imran, Hamed Merdji, Marta Fajardo, and Gareth O. Williams
Springer Science and Business Media LLC
Mukhtar Hussain, Tayyab Imran, and Ádám Börzsönyi
Wiley
The effects of thermal lensing appear to be dominant in lasing crystals as the power of optical pump pulses increases. This instigates the confined heating effects in crystals. The nonuniform distributions of temperature lead to the variability of spatial refractive index in the lasing crystals and consequently, the thermal effects become prominent. The thermal effects of Brewster‐cut Ti: sapphire crystal are measured in this study. The Ti: sapphire crystal is seeded at a wavelength of 800 nm of energy ∼7 nJ and pulse duration of ∼8 fs and pumped by the 25‐ps pulses at 532 nm operating at 80 MHz. The effects of thermal lensing at ∼40 and 293 K are measured as a function of average pump power which is controlled by the automatic attenuator. The measurements of wavefronts and aberration effects are carried out by using the Shack‐Hartmann optical wavefront sensor (HASO4). This study could pave a way to suppress the thermal lensing effects at a high repetition rate laser system and to correct the wavefront aberration for ultrahigh‐intensity and metrology experiments.
Mukhtar Hussain, Tayyab Imran, and Adam Borzsonyi
Elsevier BV
Mukhtar Hussain, Tayyab Imran, and Adam Borzsonyi
Elsevier BV
T Imran, M Hussain, H Pires, and C P João
IOP Publishing
The white-light continuum in optical bulk material has the potential to be used as a seed pulse in optical parametric amplifiers, which entails the compression of seed pulses to temporally overlap with pump pulses. An experimental study of the compression of the white-light continuum is reported in this article. Both chirped mirror compression and prism pair compression methods are used. The 280 fs pulses centered at 1053 nm are employed to generate a white-light continuum in a bulk sapphire plate; the spectrum of a white-light continuum spans from 650 nm to 1000 nm and its second harmonic generation (SHG) is measured. The scanning SHG frequency resolved optical gating technique was used to characterize the compression of the white-light continuum. Prism pair only compression of the (650–1000) nm spectra yielded 190 fs, with chirp mirrors added after leading to 150 fs. Spectral masking of the spectrum below 850 nm inside the prism compressor resulted in a pulse duration of ~120 fs for the 850–1000 nm spectral portion of the pulses.
M. Hussain and T. Imran
Wiley
We report on the 825‐nm center wavelength, 9.17 mJ pulse energy Ti:sapphire‐based femtosecond laser system simulation carried out by Lab2 tools in LabVIEW (National Instruments, Inc.). The design investigation and characterization of stretched, amplified and compressed pulses made by intensity module and second harmonic generation frequency‐resolved optical gating module in Lab2. The minimum pulse duration of ∼37.80 fs at the output of the compressor end obtained by simulations. The variation of pulse energy, FWHM and central wavelength versus number of passes in the amplifier are computed. The Lab2 tools help to design and characterize laser system before to set up on the optical table. The simulation results save time to calculate parameters which are essential in femtosecond laser system designing. The Lab2 simulation tools, along with financial constraints, it is easier, simple, and efficient to obtain results in short time.
T. Imran and M. Hussain
Institute of Physics, Polish Academy of Sciences
Thermal Lensing Compensation in the Development of 30 fs Pulse Duration Chirped Pulse Amplification Laser System and Single-Shot Intensity-Phase Measurement T. Imrana,∗ and M. Hussain Department of Physics and Astronomy, College of Science, King Saud University, Riyadh, 11541, Saudi Arabia GoLP/Instituto de Plasmas e Fusăo Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
T. Imran, M. Hussain, and G. Figueira
Wiley
The control and data acquisition of homemade, second harmonic generation (SHG) multi‐shot frequency‐resolved optical gating (FROG) diagnostic technique reported here. We have designed and developed the computer controlled multi‐shot FROG diagnostic system using reflecting optics to minimize the dispersion while LabVIEW software has employed to control and data acquisition. The femtosecond laser system at laboratory for intense lasers (L2I) optimized and characterized using LabVIEW‐based FROG system. We have measured and retrieved the oscillator and compressed amplified laser pulse profiles in temporal domains having full width half maximum (FWHM) of 150 and 270 fs, respectively, and relatively small temporal phase ∼1 radians peak to peak variations with FROG error ∼0.003. The grating detuning data acquired in the form of the single data file to observe the FROG trace pattern evaluation with the change of grating positions to confirm the reliability of the LabVIEW‐based FROG system.
Gonçalo Figueira, Joana Alves, João M. Dias, Marta Fajardo, Nuno Gomes, Victor Hariton, Tayyab Imran, Celso P. João, Jayanath Koliyadu, Swen Künzel,et al.
Cambridge University Press (CUP)
The Laboratory for Intense Lasers (L2I) is a research centre in optics and lasers dedicated to experimental research in high intensity laser science and technology and laser plasma interaction. Currently the laboratory is undergoing an upgrade with the goal of increasing the versatility of the laser systems available to the users, as well as increasing the pulse repetition rate. In this paper we review the current status of the laser research and development programme of this facility, namely the upgraded capability and the recent progress towards the installation of an ultrashort, diode-pumped OPCPA laser system.
T Imran, M Hussain, and G Figueira
IOP Publishing
We have efficiently characterized the white-light continuum (WLC) generation covering 500–900 nm in a bulk sapphire plate using 280 fs pulse duration, 1053 nm center-wavelength seed laser pulses. We have acquired the well-optimized smoother region of the WLC spectrum successfully by using an FGS-900 color glass filter (Edmund Optics, Inc.). We have suppressed the spectral components below 500 nm and over 900 nm including an intense 1053 nm residual seed laser peak of the WLC spectrum. The experimental artifacts have been avoided by suppressing the intense 1053 nm seed laser. We employed the sum frequency generation cross-correlation frequency-resolved optical gating (SFG-XFROG) technique for characterization. The XFROG measurement was carried out by introducing the crystal dithering method up to 10° in 2° intervals to obtain the phase matching effectively over the filtered and smoother region of the WLC spectrum. This well-optimized WLC region covering 500–900 nm has significant importance for use as a seed pulse in an optical parametric chirped pulse amplification (OPCPA) system.
Mukhtar Hussain and Tayyab Imran
Elsevier BV
C. P. João, H. Pires, L. Cardoso, T. Imran, and G. Figueira
The Optical Society
We generate 1.24 mJ, 390 fs pulses at 1035 nm in a CPA laser system featuring a 2.8 mJ Yb:CaF(2) regenerative amplifier, stretcher/compressor based on a single chirped volume Bragg grating and a compact, low-dispersion grating compressor. The auxiliary compressor is used to effectively pre-compensate the intra-cavity dispersion of the amplifier.
Gonçalo Figueira, Tayyab Imran, Celso P. João, Hugo Pires, and Luís Cardoso
SPIE
Optical parametric chirped pulse amplification (OPCPA) is currently one of the leading techniques for the generation of ultra-powerful laser pulses, from the multi-terawatt to the petawatt range, with extremely high peak intensities. A properly designed OPCPA setup is able to provide gain over bandwidths extending hundreds of nanometers in the visible and near-infrared, allowing the generation of high-quality, energetic, few-cycle pulses. In this paper we describe the design and performance of a compact laser amplifier that makes use of noncollinear, ultrabroadband amplification in the nonlinear crystal yttrium-calcium oxyborate (YCOB). The pump and the supercontinuum seed pulses are generated from a common diode-pumped amplifier, ensuring their optical synchronization. This laser will be used as a source of ultrashort (~20 fs), energetic (~20 mJ), tunable pulses in the near infrared.
Tayyab Imran and Gonçalo Figueira
IOP Publishing
A white-light continuum is generated in bulk sapphire using 280 fs, 1053 nm centre wavelength pulses at peak powers well above the critical power. The resulting spectrum extends from 400 nm up to at least 1100 nm with good conversion efficiency. A high-pass filter is used to remove the residual peak at the pump wavelength, producing a broad, flat spectrum in the near infrared region. We characterize the intensity and phase of the continuum by using cross-correlation frequency-resolved optical gating. We show that using pump pulses above 1 µm is a very interesting approach for generating broad continua with favourable characteristics.
T. Imran and G. Figueira
SPIE
We characterize ultrabroadband white-light continuum generated in a 10 mm block of bulk sapphire pumped by ~280 fs, ~ 1 mJ laser pulses at 1053 nm. This results in a smooth and stable spectrum, extending at least from 400 to 1100 nm. The white-light continuum is characterized by using the technique of cross-correlation frequency resolved optical gating (XFROG). We used a high pass filter to minimize the effect of the spectral components above 1000 nm of the continuum spectrum in order to avoid experimental artifacts caused by the intense 1053 nm peak, and we observed good agreement between the retrieved and directly measured spectra.
A. B. Sardinha, E. Abreu, J. M. Dias, D. Douillet, G. Figueira, T. Imran, M. Kozlova, N. Lemos, N. C. Lopes, J. Miranda,et al.
AIP
X‐ray lasers are a very useful tool producing a large quantity of data quickly and that can be used on many applications. Through seeding the X‐ray laser (XRL) with a High Harmonic beam, the XRL will act as an amplifier of high‐optical quality beam keeping the properties of the Harmonic while saturating at a shorter length. High Harmonics should however be tuned in order to match the wavelengths of the existing X‐ray lasers. We present the results of the generation of tunable high‐order harmonics by changing the pulse compression. We have obtained High harmonics up to the 51st order interacting a strong Nd‐glass laser field with argon atoms in a gas cell. A shift of 13% around the central wavelength was observed allowing us to reach the Ne‐like Mn and the Ne‐like Fe lines via high harmonic generation (HHG). A study of the linear chirp was also performed.