I have always been a fan of science fiction. A ubiquitous element of that literature is the use of powerful lasers as weapons.
Over the last year, I spent several months reading David Weber’s Honor Harrington series of novels. Weber’s stories prominently feature space-based navies battling with lasers across vast distances.
It was understandable then that two recent events piqued my interest. The first was the publication of the paper entitled “Temperature rise in objects due to optical focused beam through atmospheric turbulence near ground and ocean surface” in the March issue of Optical Engineering.
The second was the announcement in early April that the U.S. Navy would be deploying a high-power laser weapon on a ship (see below).
Due to the close conjunction of its publication with the Navy announcement, I believe this open-access paper will be of general interest to the Optical Engineering community.
The authors, Matthew Stoneback, Akira Ishimaru, Colin Reinhardt, and Yasuo Kuga, all affiliated with the University of Washington (USA), provide a detailed model for the amount of heating obtainable in some common materials using high-powered lasers over tactically significant ranges and under atmospheric conditions.
The article is well referenced, providing the reader excellent resources for digging deeper into the body of research that underpins this work. The essence of the work is the combination of optical-intensity calculations at range, through turbulence, and the subsequent calculation of the propagation of heat through the material.
Using these calculations, the researchers show how some common materials can be brought to destructive levels of heating through the use of a high-power CO2 laser. Key parameters such as the power level and dwell time necessary to melt or boil materials are illustrated through informative plots.
Focused beam and object, from Optical Engineering.
As high-power lasers become more prevalent, the information and models contained in this article may prove useful for engineers considering their deployment in a variety of military and perhaps civilian applications.
Source: Optical Engineering 52(3), 036001 (2013); doi: 10.1117/1.OE.52.3.036001.
–SPIE Fellow Eddie Jacobs of University of Memphis is a member of the Optical Engineering editorial board.
U.S. to test new laser weapon
The U.S. Navy announced in April that it would test a new laser weapon system next year aboard a ship in the Persian Gulf.
Admiral Jonathan Greenert told the House Armed Services Committee that the prototype weapon would be capable of disabling small vessels and shooting down surveillance drones.
The directed-energy weapon will be mounted on the USS Ponce, an amphibious transport and docking ship retrofitted as a waterborne staging base.
Special section on high-energy lasers
A special section on high-energy laser (HEL) systems and components in the February issue of Optical Engineering surveys current technologies and challenges of HEL weapons development, along with providing a historical perspective on the technology.
Several articles are open-access. Topics covered include the utility of HEL weapons and:
- The physics behind free-electron lasers and the unique problems encountered when increasing average power
- Optical and pointing requirements placed on an HEL beam-control system and the evolution in performance and approaches used to meet those needs
- Problems that tactical laser systems encounter when scintillation and anisoplanatism complicate the wavefront measurement process
In “High-power diode-pumped solid-state lasers,” SPIE member Steven Bowman of the U.S. Naval Research Lab discusses the materials properties enabling today’s capabilities in high-average-power bulk lasers and the uses of solid-state lasers in manufacturing, communication, biomedical, and defense applications.
Addressing the problem of energy loss, “Ceramic windows and gain media for high-energy lasers” by Woohong Kim and other researchers provides an overview of the development of new ceramic materials.
John Albertine, former leader of the U.S. Navy’s High-Energy Laser Program Office is guest editor.