Mohsin Haji
Principal Scientist
Mohsin Haji is a Principal Scientist in the Time and Frequency department at NPL. He obtained a BEng honours degree from City University London in 2007 and a PhD from the University of Glasgow in 2012. He has authored and co-authored over 80 peer-reviewed publications and is a reviewer for several IEEE and OSA journals.
Mohsin leads NPL’s activities on the development of next-generation holdover atomic clock technologies in collaboration with several manufacturing companies.
Areas of interest
- Portable atomic clocks for position, navigation and timing (PNT) applications
- Electronic servo systems for adaptive stabilisation and control, e.g. Pound-Drever-Hall technique
- Semiconductor laser diodes (particularly single-mode and mode-locked lasers) and optoelectronics
- High-frequency optoelectronic oscillators for GHz and THz generation
- RF systems design, complex impedance matching circuits, and high frequency antenna designs
- Optical transceiver systems for telecoms/datacoms
Key publications:
- Holdover Atomic Clock Landscape Review
M. Haji, I. Hill, E.A. Curtis, P. Gill National Physical Laboratory Report TQE 32, (2024) - High frequency optoelectronic oscillators based on the optical feedback of semiconductor mode-locked laser diodes
M. Haji, L. Hou, A. E. Kelly, J. Akbar, J. H. Marsh, J. M. Arnold, and C. N. Ironside
Optics Express, 20 (3), 3268-3274, (2012) - GaN laser technology for cold-atom quantum sensors and optical atomic clocks
S.P. Najda, P. Perlin, T. Suski, S. Stanczyk, M. Leszczyński, S. Schiavon, T. Slight, S. Gwyn, S. Watson, A.E. Kelly, J. Macarthur, L. McKnight, M. Knapp, M. Haji
Optical Sensors, SW4I. 4, (2021) - Dynamic Device Characteristics and Linewidth Measurement of InGaN/GaN Laser Diodes
S. Gwyn, S. Watson, T. Slight, M. Knapp, S. Viola, P. Ivanov, W. Zhang, A. Yadav, E. Rafailov, M. Haji, K. E. Doherty, S. Stanczyk, S. Grzanka, P. Perlin, S. P. Najda, M. Leszczyski, A. E. Kelly
IEEE Photonics Journal 13 (1), 1-10, (2020) - Laterally coupled dual-grating distributed feedback lasers for generating mode-beat terahertz signals
L. Hou, M. Haji, I. Eddie, H. Zhu, J.H. Marsh
Optics letters 40 (2), 182-185, (2015)