Evaluation of 976 nm Multimode Single Emitter Laser Diodes for Efficient Pumping of 100 W+ Yb-doped Fiber Laser

  • Rishi Kant Sharma Laser Science and Technology Centre, Delhi
  • Shammi Wadhwa Laser Science and Technology Centre, Delhi
  • N.K. Verma Laser Science and Technology Centre, Delhi
  • M.N. Reddy Laser Science and Technology Centre, Delhi
  • H Rana Amity University Uttar Pradesh, Noida
Keywords: Laser diode, Fiber laser, High power lasers, Yb-doped fiber laser

Abstract

Experimental evaluation of spectral and power-current (P-I) characteristics of fiber coupled single emitter multimode laser diodes used for development of efficient pumping assembly is reported. Fiber coupled laser diodes emitting around 976 nm are best suited for pumping Yb-doped fiber lasers because of excellent coupling efficiency and reduced thermal load. We have experimentally investigated emission spectrum of fiber coupled multimode laser diodes at different temperatures and drive currents. It is found that peak emission wavelength shifts towards the longer wavelength with increase in temperature and drive current. P-I characteristics of fiber coupled laser diodes have been obtained and presented for drive current from 0.4 A to 11.5 A. Based on experiment, we have constructed spectrally matched laser diode assembly for efficient pumping of 100 W fiber laser. It requires very precise control of temperature and drive current to maintain the emission spectrum. Total 162 W power is pumped in to the Yb-doped fiber laser cavity through multi-mode pump combiners and we have obtained 110 W fiber laser output power @1070 nm. The achieved optical-to-optical efficiency is 68 per cent.

Author Biographies

Rishi Kant Sharma, Laser Science and Technology Centre, Delhi
Mr Rishi Kant Sharma, obtained BE (Electronics) from Motilal Nehru Regional Engineering College (MNREC) Allahabad, University of Allahabad, Allahabad & MTech (ECE) from Amity University Uttar Pradesh, Noida. Currently working as Scientist ‘D’ in the High Power Fiber Laser Group, LASTEC, Delhi. He has worked in the area of Free Space Optical Communication, development of exciter systems for CO2 Laser, LIDAR and associated detection electronics. His current areas of interest are : High power laser diodes, laser diode drivers and high power fiber lasers for tactical applications.
Shammi Wadhwa, Laser Science and Technology Centre, Delhi
Ms Shammi Wadhwa, obtained his MSc (Electronics) from Delhi University, Delhi. Presently working as Scientist F, in the High Power Fiber Laser Group at LASTEC, Delhi. She has worked in the area of RF amplifiers, free space optical communication, TEA CO2 Laser and LIDAR. Her current research interest are : Free space laser communication, high power laser diodes, kW class fiber lasers and amplifiers and photonic crystal fiber for defense applications.
N.K. Verma, Laser Science and Technology Centre, Delhi

Mr N.K. Verma obtained his MSc (Physics) from Delhi University, in 1985. Presently working as Scientist G, in the High Power Fiber Laser Group at LASTEC, Delhi. His current research interests are development of high power fiber lasers and beam combining technologies for tactical defense applications.
M.N. Reddy, Laser Science and Technology Centre, Delhi
Dr M. N. Reddy, obtained his MSc (Physics) and M.Phil (Physics) from Central University of Hyderabad and PhD (Laser High Resolution Spectroscopy) from IIT, Kanpur. Presently working as Scientist G, and heading High Power Fiber Laser Group at LASTEC. His current research interests are : Development of high power fiber lasers and laser spectroscopy techniques for stand-off detection of explosives.
H Rana, Amity University Uttar Pradesh, Noida

Mr Haneet Rana received the MTech (Signal Processing and Control) from National Institute of Technology, Hamirpur, in 2011. Currently, he is an Assistant Professor of Electronics and Communication Engineering at Amity School of Engineering and Technology, Amity University, Noida. His research interests include: Statistical estimation and detection with applications to the imaging sciences, signal processing, scientific computing, and mathematical optimisation.
Published
2016-12-23
How to Cite
Sharma, R., Wadhwa, S., Verma, N., Reddy, M., & Rana, H. (2016). Evaluation of 976 nm Multimode Single Emitter Laser Diodes for Efficient Pumping of 100 W+ Yb-doped Fiber Laser. Defence Science Journal, 67(1), 88-93. https://doi.org/10.14429/dsj.67.9962
Section
Electronics & Communication Systems