Pumping a Thin-Disk Laser

The thin-disk laser is a special type of high-power diode-pumped solid-state (DPSS) laser. Ytterbium-doped YAG (Yb:YAG) is often used as the active laser medium, lasing at 1030 nm, with a broad, 18 nm wide absorption band at 940 nm. It is one of the most useful media for high-power diode-pumped solid state (DPSS) lasers. The Yb dopant levels may range between 0.2-30% of replaced yttrium atoms. Yb:YAG has high mechanical strength and high thermal conductivity. Yb:YAG can be pumped by reliable InGaAs laser diodes at 940 nm.  Figure 1 shows a thin-disk being pumped and the laser beam exiting the module.

Figure 1. Typical Thin-Disk Module

The diode-pump laser gain medium, Indium gallium arsenide (InGaAs), is a semiconductor composed of indium, gallium, and arsenic lasing at 940 nm.  Figure 2 shows a typical laser diode array.

Figure 2. Laser Diode Array

At Applied Energetics, for diode pumping our thin-disk lasers, we've been using nLight Inc. or Laserline Co. laser diode arrays.

For more information go to  www.appliedenergetics.com

What is an Ultrafast Laser?

Ultrafast lasers (UFL) emit ultrashort pulses with durations of femtoseconds (10^-15 s) to picoseconds (10^-12 s). They are also known as ultrashort pulse (USP) lasers or femtolasers.

A femtosecond (10^-15 seconds) is one quadrillionth, or one millionth of one billionth of a second.  A femtosecond compares to a second, as a second compares to 30 million years.

Figure 1. Light is so fast that it can circle 

the earth 7 times in only one second.

Figure 2. In 100 femtoseconds light only

crosses a hair width

UFL’s have a wide range of industrial applications including:

-          material processing

-          micromachining

-          microfluidics fabrication

-          solar thin films

-          biosensors fabrication

-          waveguide writing

-          medical treatments

-          laser microscopy

-          tomography

We can compare the position of the femtosecond laser just a few years ago with how “conventional wisdom” perceived the Internet back in the early 1990s: “hardly anybody anticipated that so many people the world over would depend on the web for shopping and entertainment, communications and work.”

But an Internet-style turnaround is happening to the ultrafast laser. The past 20 years of femtosecond R&D is now finding applications in “cold” ablation- notably the drilling and cutting of high precision holes (such as in the production of medical stents) free from thermal damage.  The ultra-fast lasers essentially vaporize matter without generating heat- creating new ways to machine materials. They are particularly good at machining very small, very precise patterns in tough materials.


For more information go to  www.appliedenergetics.com