Introduction

This team specialises in the science, technology and engineering of all-solid-state light sources. Current interests include:

• Mid-IR semiconductor disk lasers (VECSELs) for chemical sensing and free space communications
• Maximising laser power output through thermal modelling and thermal management techniques
• Pumping configurations: improving system efficiency and high average power operation
• Engineering systems: designed for compactness, high reliability and low maintenance; active intra-cavity elements for frequency and spatial mode control
• New laser materials: increasing spectral coverage and tunability
• Using adaptive optics within laser cavities to optimise beam quality

In laser engineering, we focus on systems with specifications that are of (potential) interest for particular industrial and/or scientific applications. The transfer from the laboratory demonstration of a new system or principle into a production prototype always presents significant challenges. It is in these areas that this team operates, investigating and developing new technical solutions that enable the devices to progress to leading edge custom systems and/or new products.

Current Research

Intra-cavity adaptive optics

We are exploring the active control of laser output to make lasers more practical. Beam quality can change with time, especially at start-up and when the device heats up, lensing effects can adversely affect the beam quality. By using a variety of algorithms and learning methods, we can actively control the beam quality to ensure that useful output is achieved quickly upon start up. We can also maximise beam quality throughout the lifetime of a laser product.

The key advantages for the laser manufacturer are reduced costs in other components, ease of alignment, more latitude in the specification of the laser, and greater time intervals between service and maintenance. For the laser user, reduce service and maintenance are also advantageous and the laser output can be more consistent day to day and over longer periods.

Mid-IR semiconductor disk lasers (VECSELs)

Semiconductor disk lasers have demonstrated great wavelength versatility and our work at the IOP has extended this through 1.3 to 2.2microns. The modest output powers of semiconductor disk lasers (we have achieved 1W at 2.2 microns) are more than adequate for free space optical communications and environmental sensing. There is a convenient window of atmospheric transmission at 2.2 microns and semiconductor disk lasers at this wavelength can be made small, robust and relatively inexpensive.

Advanced Disk Lasers:

Diode-pumped solid-state lasers in disk formats are ideal for applications such as cutting and welding – their relative insensitivity to thermal problems means they can be scaled to very high powers. However, this power scalability is bought at the cost of increased complexity: the pump light must be recirculated to compensate for the thin laser gain medium. In this project, we aim to harness the thermal management advantages of the disk geometry – but reduce complexity and develop practical, higher-power finesse lasers, particularly for sensing applications. By integrating high thermal conductivity materials like diamond, we can improve thermal management; by using materials that strongly absorb the pump light, we can improve practicality; by developing monolithic laser geometries, we can design lasers that are more robust; by applying these thermal management technologies to semiconductor gain media, we can engineer lasers for the wavelengths required by important applications.   

Single page summary for the following topics are available to download as pdf
High Power Laser Research - click here
Quasi-CW Laser Research - click here
Alan Kemp's MSc Lecture: Semiconductor disk lasers: The future's bright; the colour's flexible- click here

Research Team		Publications
Dr David Burns	Associate Director
Dr Alan Kemp	Associate Team Leader and Royal Society of Edinburgh Research Fellow
Dr John-Mark Hopkins	Senior Researcher
Dr Patricia Millar	Researcher
Dr Walter Lubeigt	Researcher
Nils Hempler	Researcher
Alex MacLean	Phd student
Micheal Poulter	EngD student