EPSRC logo

Details of Grant 

EPSRC Reference: GR/H15264/01
Principal Investigator: Sibbett, Professor W
Other Investigators:
Researcher Co-Investigators:
Project Partners:
Department: Physics and Astronomy
Organisation: University of St Andrews
Scheme: Standard Research (Pre-FEC)
Starts: 01 September 1992 Ends: 29 February 1996 Value (£): 68,286
EPSRC Research Topic Classifications:
Optoelect. Devices & Circuits
EPSRC Industrial Sector Classifications:
Aerospace, Defence and Marine Communications
Related Grants:
Panel History:  
Summary on Grant Application Form
In this collaborative research project (with Professor Whites group, School of Physics, Bath University) the principal aims have been directed towards the generation of picosecond/subpicosecond pulses at high repetition frequencies from diode laser configurations. Particular emphasis relates both to novel external-resonator configurations for conventional laser chips and to multi-segment designs of laser diode components.Progress:To address the requirement to achieve a high repetition rate (in the GHz regime) several pulse generation schemes have been evaluated. At St Andrews we have investigated novel external-cavity configurations by which multi-GHz repetition frequencies have been demonstrated within pulse packets which recur at a cavity frequency up to ~1GHz[1]. The mechanism of this multipulse generation technique is being studied in ongoing research.In collaboration with Professor White, we have been concentrating on the assessment of multiple-segment diode lasers in which sections for gain and loss are provided. To date, Q-switching and mode locking methodologies have been applied for the generation of picosecond/subpicosecond pulses in spectral ranges around 850nm and 1500nm. The characterisation of intensity profiles using electron-optical streak cameras has been an especially relevant contribution to this work. With regard to the Q-switched picosecond pulse-generation, our project has yielded the production of symmetrical temporal profiles with correspondingly high-quality spectral characteristics for pulses having timing-jitter as low as ~1ps[2]. This has been achieved by implementing a novel forced Q-switching technique. In our collaborative modelocking studies, flared and flare-taper 'bow-tie' device structures (designed at Bath University) are being assessed. Interestingly, subpicosecond pulses can be generated in such lasers at repetition rates 2100 GHz. The present aim is to optimise the peak pulse powers from these devices so that they can be used in ultrafast optoelectronic switching applications. For applications where the spectral quality of the ultrashort diode laser pulses is of paramount importance, we are implementing a scheme of coupled-cavity-pulse seeding [3]. The simultaneous monitoring of the temporal and spectral characteristics of the pulses from an external-cavity InGaAsP diode laser is indicating for the first time that this technique is applicable to diode lasers. 1 W. Sibbett, 1994 Annual Meeting of Opt.Soc. America, Dallas, Texas, Paper TuA12 K .A. Wilkins, I.H. White, D. Burns and W. Sibbett, Proc. LEOS 94, Paper U03-4, 1994, Boston3 G T Kennedy, G Valentine and W Sibbett, accepted for presentation at CLEO 95, May 1995, Baltimore
Key Findings
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
Potential use in non-academic contexts
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
Description This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
Date Materialised
Sectors submitted by the Researcher
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
Project URL:  
Further Information:  
Organisation Website: http://www.st-and.ac.uk