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| "In order to overcome the biggest challenges you have to overcome your own fears.” Profound philosophy coming from a 30-year-old. Daniel Esser, a scientist at the CSIR National Laser Centre, is truly an exemplary individual – he scooped the 2006 CSIR National Laser Centre Achievement Award for a Promising Young Researcher and is already a respected scientist in his field. He has also gained international recognition for his leadership in a project where laser technology was applied in a defence context. This project team clinched the 2006 CSIR Excellence Award for an Outstanding Contribution by a Team. |  |
Daniel's work
| Daniel is involved in the research of solid-state lasers and devices. Daniel says, “The aim of this research is to generate knowledge about designing and demonstrating a solid-state laser, which is efficient and compact. Explaining solid-state lasers, Daniel says that all lasers have an active medium, and in the case of a solid state laser, the active medium is not a gas or a liquid, but often glass or a crystalline host material doped with an active ion to enable the light amplification through stimulated emission of radiation. We have been evaluating the current status of laser sources and are now focusing on the design of a diode-end-pumped laser with its output wavelength at 2 µm.” |
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“There are several applications that can benefit from this new laser technology, which, when employed, could have a significant impact in a number of fields. One such application is laser surgery. In the wavelength region in which we have recently demonstrated the Tm:GdVO4 laser, e.g. wavelength selection from 1.8 µm to 1.9 µm, the water absorption coefficient changes dramatically. Since human tissue is mostly water, this wavelength tuneable laser can be used to great benefit as a 'depth-selective' laser scalpel,” Daniel says excitedly. Daniel says, “Another advantage of the 2 µm spectral region is that it is so-called 'eye-safe' and, when set to a suitable wavelength, can have a low absorption by the atmosphere. | 
Daniel at the CSIR Excellence Awards. |
In contrast to a typical 1 µm laser source, which is highly dangerous to the eye, a 2 µm laser could be used safely and efficiently for any laser application that requires long distance propagation through the atmosphere. As such, laser devices used for remote gas detection regarding environmental monitoring, direct line-of-sight communication, range-finding and illumination, can all potentially utilise the new high-power 2 µm laser technology being developed by the CSIR.”
Daniel explains, “Although 2 µm lasers have been known for quite some time, it was mainly due to the improvement of diode laser technology that scientific interest in these lasers has grown significantly over the past few years.” High power diode lasers with controlled beam quality have allowed for the development of laser systems that were previously not feasible. One such laser system is based on Tm3+ as the active laser ion, which can be operated with high efficiency when pumped with a laser diode. In addition, good beam quality can be achieved when a solid-state laser is pumped longitudinally along the optical axis.”
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“The interest in a compact, efficient and potentially rugged laser in the 2 µm region for scientific applications should not be underestimated. Very few laser sources exist in this wavelength region, and is currently only catered for by cumbersome, expensive or very low-power systems on the commercial market. With sufficient funding and resources, a commercial laser system could be developed directly from the mid-infrared lasers demonstrated by the research team,” he adds.
Part of the 2 µm laser design is based on the novel ideas that evolved during the development of diode-end-pumped solid-state lasers producing output in the 1 µm spectral region. Daniel proudly says, “These Nd3+-based lasers were developed collaboratively by the CSIR National Laser Centre and the Laser Research Institute at the University of Stellenbosch. They were successfully integrated at the CSIR into a technology demonstrator, producing a unique laser system that is world-class. This technology is now being developed to the next level, where the needs of very challenging applications in the mid-infrared are bring addressed.”
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Daniel at work |
Why lasers?
| As a teenager growing up in Parkview, Johannesburg, Daniel did not know that his career would involve physics. He loved mathematics at school and it was only after being exposed to undergraduate physics that he realised where his true passion lay. The now senior scientist was a dedicated student at the University of Stellenbosch and as such, received his BSc Honours and MSc in laser physics cum laude. Says the man with the gentle disposition, “I feel blessed with all the opportunities and accolades that I have received. I only try to do my best with the support of my family and colleagues. I am honoured that I have been able to live up to their expectations.” While working towards his MSc, Daniel decided to focus his studies on laser device physics and selected this as a project. | 
His first laser |
He received a two-year bursary for his postgraduate study from the CSIR National Laser Centre and in 2003 received a prize for the best MSc student presentation at the Conference on Optics and Laser Applications in Namibia.
In 2005, soon after he had joined the CSIR, he received a grant from the CSIR Young Researcher Establishment Fund for the research and development of compact mid-infrared laser sources. He is now working towards his Engineering Doctorate in Photonics via Heriot-Watt University in Edinburgh, Scotland. It appears that laser research was his destiny after all. To date, Daniel has presented nine research papers internationally; and 19 nationally.
Daniel's life beyond the CSIR
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Whilst studying in Stellenbosch, Daniel taught Sunday school to children living on farms outside the town. “It is so rewarding to give while not expecting to get anything back. I liked being able to reach out to disadvantaged kids like that.” Daniel's high school sweetheart, Irene-marie, is now his wife and they have been married for almost five years. Not to be overshadowed by her husband, Irene-marie has an international Master’s degree in law and is currently a senior commercial law lecturer at Unisa. She will complete her doctorate in law soon. The couple enjoy travelling and are fortunate that both their jobs afford them the opportunity to explore the world. Thus far, Daniel has been to Algeria, Australia and many countries in Europe. The couple are off to New York for two weeks in June this year; something that Daniel is looking forward to. | 
The happy couple |
You can also be sure to spot Daniel at restaurants renowned for their good food as the man loves to eat out and experience the different flavours that South Africa has to offer.
The future of his research
“I am focusing on the development of a laser source, and not a whole system. I want to really get it out there; used by industry and making a real impact on the use of lasers in South Africa. Our laser sources need to become commercialised but because of limited resources and expertise in the country, we are not there yet. The future, however, is promising.” He adds, “I like to take on a challenge removed from the norm. I always want to try something new and with the calibre of scientists specialising in lasers at the CSIR, this is possible. I also love the experimental work that this type of research offers; it is fun and stimulating. There is a good interface between physics and engineering, which is fantastic.”
More information on his research is available at http://www.csir.co.za/lasers/lasersystems.html
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