The Laser and Fibre Optics Centre (LAFOC) located at the Department of Physics of the University of Cape Coast has been existence since March 1993 as an affiliated centre of the Abdus Salam International Centre for Theoretical Physics (ICTP). It is one of two ICTP regional centres of excellence in applied optics (lasers) and spectroscopy that were established with financial assistance from the governments of Italy and Sweden and the ICTP to serve the West African Sub-Region: one in Cape Coast, Ghana, for the support of the Anglophone countries and the other in Dakar, Senegal, for the Francophone countries. Funding
Main funding sources for LAFOC are:
* University of Cape Coast: Provides salaries of staff and basic infrastructure such as laboratory space and some support towards the running expenses of the centre.
* ICTP - Office of External Activities (OEA): Annual grant of US$ 25 000 towards fellowship grants to graduate students, acquisition of equipment and textbooks. Small grants and donations are also received from: * Third World Academy of Sciences (TWAS): Grants for research projects.
* International Programme in Physical Sciences (IPPS), University of Uppsala and Lund Institute of Technology,
* Sweden: Support for research projects and PhD programmes in applied spectroscopy.
* National Institute of Applied Optics, Italy: Contributions in terms of optical components and detectors.
* Optical Society of America: Educational material and optical design software
The Centre aims at expanding its basic and applied research by focusing on applications in agriculture, environment and the local industry since there are already strong linkages of the Centre to research groups both in Europe and Africa. The Centre requires an upgrading to enable it face challenges in the advancing technologies in Optics. As such new equipment in the form of short pulse and powerful lasers would be acquired. The Centre will be opened up to researchers in Africa to enable them use the facilities to solve some common problems. Our local collaborators such as Tema Oil Refinery and Ghana Atomic Energy Commission in the area of pollution would be strengthened. The Centre hopes to link up with the National Laser Centre in South Africa so that students of LAFOC will have the chance to use the facilities of that Centre. More Scientists will be encouraged to have collaboration with the Centre. The Centre is grateful to Prof. G. Denardo and staff of OEA of ICTP, Prof. F. T. Arecchi, of INOA, Firenze, Prof. F. K. A. Allotey and Prof. S. K. Adjepong for their assistance and encouragement in making the projects at the Centre successful.
Infrastructure And Equipment:
LAFOC is housed at the Department of Physics and occupies three medium size research laboratories, a small photographic laboratory, office space and a reception area, also used to accommodate the secretary and part of the computer facilities. Although facilities appear sufficient at the present level of activities, there is little room for expansion. If activities need to be expanded or additional ones be introduced, new larger laboratories would have to be found. The laboratory has a good selection of optical components and opto-mechanical hardware, such as lenses, filters, optical mounts and translation stages. Optical tables are locally manufactured, but adequate for the type of experiments performed. Optical detectors and basic electronic equipment such as function generator, lock-in amplifier and a selection of slow and medium speed (<250 MHz) oscilloscopes are available. Spectroscopic equipment includes an Ocean Optics spectrograph. Available laser systems are limited to a 75 mW HeNe laser, a selection of low power laser diodes and HeNe alignment lasers. The centre is well equipped with computer equipment, including laptop computers for the control of experiments. Sophisticated optics and laser design software (GLAD) is available to the centre through a donation of the Optical Society of America (OSA). A large number of specialised books and journals has been made available to the centre through the ICTP Book and Journal Donation Program and the annual OEA grant. Most of the equipment available to the centre has been purchased from funds provided by the ICTP and the Swedish International Programme in Physical Sciences (IPPS) with a smaller portion funded by the Atomic Physics Division in Lund. Although the available infrastructure appears to be satisfactory for the currently carried out projects there is a strong need for more sophisticated equipment in order to be able to expand research efforts, in particular in the field of spectroscopy. In the short term equipment of highest priority includes: * High Power Nd:Yag laser as excitation source for LIBS * Tuneable laser for laser spectroscopy * UV laser for fluorescence studies * Fast oscilloscope (500 MHz - 1 GHz) In the longer term a femtosecond laser system would also be desirable. Ghana has a developed research infrastructure and culture, as demonstrated by a well defined Research and Technology Development (RTD) strategy and active research organisations such as the CSIR Ghana and the Ghana Atomic Energy Commission. There are also several universities with a relatively strong research component in the science and technology field. The Laser and Fibre Optics Centre (LAFOC) at the Department of Physics of the University of Cape Coast has been operating since 1993 as an affiliated centre of the ICTP and has since then developed into a regional centre providing support in the fields of optics, lasers and spectroscopy. The centre carries out relevant basic and applied research focusing at applications in agriculture and the local industry. There are strong linkages of the centre to research groups in Sweden and Italy. The existing infrastructure of the centre in respect of personnel and equipment is adequate for the existing research projects, but would require upgrading if additional support functions, in particular in the direction of equipment maintenance and repair, would have to be carried out. There appears to be good support from the government of Ghana and also from the University of Cape Coast for the African Laser Centre and for the plan to establish a Regional User Facility of the ALC at LAFOC. It is likely, that the UCC would be prepared to provide additional laboratory space, or even a dedicated building for the centre.
Major areas of concern to the Centre are:
1. Optical metrology in the areas of Image Processing, Interferometry and Applied Spectroscopy.
2. Tissue optics as applied to Tomography, and Light Scattering on soft tissue or turbid media.
3. Fibre Optics at the Centre on Optical Fibre communications and sensing.
4. Numerical simulations using OSLO and GLAD fro Laser and Optical Design as well as Monte Carlo calculations for tissue optics.
LAFOC has hosted several international workshops in Cape Coast:
1. 3rd International Workshop on the Physics and Modern Applications of Lasers, 8-20 August 1994, Cape Coast, GHANA
2. ICS-UNIDO Workshop on Combustion Diagnostics and Optical techniques (International Centre for Science and High Technology - United Nations International Development Organization), July 1999, Cape Coast, GHANA
3. ICS - UNIDO second Regional Workshop on Monitoring of Air Pollution due to Combustion Processes, 30 October - 4 November 2000, Cape Coast, GHANA
4. ICS – UNIDO Training Course on Fibre Optics for Optical Fibre Communications, Cape Coast, Ghana, 10 – 14 October 2005.
Programmes in research will be basic as well as applied to the industry. In broad terms, areas of research will focus on
1. Applied spectroscopy on biological objects
2. Optical metrology in industry and environment
3. Imaging Optics
4. Optics Education Our research activities will like be dwelt on chlorophyll Fluorescence as applied to Agriculture and biological objects. Through the assistance of IPPS and Lund Institute of Technology a blue diode Laser Fluorometer was assembled at Lund and has been used as an initial investigation into this project. The aim here is to measure the chlorophyll fluorescence kinetics in full daylight to obtain information on the function of the photosynthetic apparatus of some variety of tropical plants (cowpea, tomatoes, cassava, okro etc) on the field. By so doing, the variety of the crop that is good for higher yield can be classified. This can be achieved by using the minimum and maximum Fluorescence signals Fo and Fm respectively and also the peak ratios of the fluorescence signals. The Fluorescence changes that occur in such green leaves are correlated with the photosynthetic assimilation. Applications of such method will include:
1. in vivo and in-vitro photosynthesis in plants
2. screening of plant breeding and production
3. Air pollution studies and its effects on photosynthesis
4. Demonstration of chlorophyll Fluorescence and photosynthesis to students Initial work in this area has been done by Mr. S. S. Sackey and Mr. Ben Anderson under the M.Phil thesis programme. Most of these areas have been earlier on been investigated and detail work will now be be done in this vision which will have immediate importance to the national economy.
Photon migration in diffusing media:
Development of experimental set up for measurement of optical properties of diffusing media based on low cost continuous wave instrumentation for quality analysis of fluids will be done. By measuring the absorption coefficient at different wavelengths of the diffusing medium the concentration of different components in the scattering medium (sample) could be determined. In addition, in order to be familiar with photon migration in diffusing media, a perturbation model will be used to study the diffuse reflectance using Monte Carlo simulations and experiments. A CW HeNe Laser will be used to measure the mean path followed by received photons inside a generic volume element of the medium and the probability that received photons passed through a generic volume element of the medium. This system can be used to study the inverse problem to reconstruct the optical properties of the inhomogeneities in the medium in close comparism with Monte Carlo simulations as well as experiments on phantoms to understand optical tomography. Under the assistance of ICTP and IAEA sandwich programme, Ms. M. Tahani Mohammed has graduated in this under the guidance of Prof. G. Zaccanti of Department of Physics, University di Firenze
Simple experimental set up by making use of 2 Ronchi rulings will be used to study the Moire deflectometry. A Moire deflectometer is a quantitative instrument for mapping ray deflections caused by refractive index gradients in phase objects or height gradients on reflective surfaces and transparent objects. The technique is based on the Moire effect, a phenomenon that causes a moiré fringe pattern to appear when two gratings are placed at a small angle to each other. A collimated beam that passes through a phase object is deflected through the gratings. Such system can be used to
(i) test strain induced deflection
(ii) test optical collimation
(iii) reflective surface analysis
(iv) refractive index and focal length of glass materials With these applications emphasis will be direct on flame diagnostics, textile strains and surface cracks. Research work will be initiated with the industry with M.Phil students assigned to the project. M. J. Eghan has used Fourier correlator to study track in LR-115 and CR-39 detectors
A set up using light emitting Diode and a photodiode with some electronics could be used to study the vibration and displacement of objects. Such a system is to help in basic research and expose young scientist to basic concepts in interfacing and programming. In addition, possible devices could be studied with this technique. Among them is the CD pickup to do surface profiling as well as to understand other system in optical fibre communications. Michael Vowotor has started this work and yet to graduate. Other M. Phil students have been assigned to this work and will be assisted in supervision by visiting scientist Dr. B. Tiribilli of Istituto Nazimale di Ottica applicata Firenze.
It is our hope and desire that DOAS or LIDAR could be obtained to study gaseous emissions from automobiles, industries and biomass in the cities and the rural areas of Ghana. The essence of this study is to integrate the techniques of DOAS and FTIR systems to measure gas absorption and gas concentrations. Scientists at LAFOC will be used on these experiments. All these research topics being or yet to be carried out at center are to engage graduate and post doctorate students in these studies.