Diffractive Optical Elements (DOEs) are lightweight, thin optical components with many applications in laser beam-shaping.
In this paper we consider the application of DOEs for coupling of high power Nd:YAG laser light to fibre
For the laser system in question intra-cavity DOEs are considered for the generation of a super-Gaussian cavity mode,
while an extra-cavity element is considered for shaping the beam to produce a profile suitable for fibre coupling.
The arrangement to be considered in our application involves coupling a 100mJ, 20ns pulse laser beam of 5mm diameter
into 3 fibres, each with a core diameter of 400μm, positioned in an equilateral triangle formation with a centre to centre
spacing of 2mm. The threshold power density for the fibres is 4.5GW/cm<sup>2</sup>.
512x512 pixel DOEs with 16 phase levels have been optimized using the iterative Fourier transform algorithm (IFTA).
The optimized element produces spots with a radius of 14 diffraction orders. The modeled efficiency of the element is
91.4% with a peak power of 1.26GW/cm<sup>2</sup>. Experimental measurements using a low power 633nm source equate to a
peak power of 2.65GW/cm<sup>2</sup> for the high power laser, well within the damage threshold.
The laser diode was first developed in 1962, since which its design and some of the initial concepts have changed vastly.
Improvements in laser diode technology have assisted in the development of many modern day technologies, ranging
from remote sensing instruments to highly efficient pumping of other laser systems. As technologies where laser diodes
can be applied advance, it is important to understand the behaviour of the laser diode in such environments which may
become more hostile or complex.
This paper presents information and data from literatures published on previous investigations carried out on laser diodes
under the influence of neutron, gamma or X-ray irradiation. Any behavioural trends will be observed, as will any
abnormalities to provide a succinct review of the laser diodes in these environments, and allow for predictions or further
investigations into this subject to be made.
The area of display devices has experienced extremely rapid growth in recent years and these advances show no sign of declining. One of the major developments in this field has been the use of lasers for various microfabrication tasks. This paper describes some techniques which have been developed using excimer lasers for the production of novel microstructures in polymer materials. Examples of the types of microstructures which are produced are presented and their applicability for display device applications is outlined. Forthcoming developments in the laser manufacture of displays are discussed.
Conference Committee Involvement (3)
Optical Technologies for Arming, Safing, Fuzing, and Firing V
5 August 2009 | San Diego, California, United States
Optical Technologies for Arming, Safing, Fuzing, and Firing IV
13 August 2008 | San Diego, California, United States
Optical Technologies for Arming, Safing, Fuzing, and Firing III
29 August 2007 | San Diego, California, United States