LLTI takes delivery of Ultrafast Laser

Applied Energetics (AE) has delivered an Ultrafast "Leopard" Laser system to Laser Light Technologies, Inc. (LLTI) in Hermann, Missouri, USA.  http://www.laserusa.com/   LLTI specializes in high-technology laser micromachining services as well as R&D.  

Laser Light Technologies in Hermann, Missouri

The Leopard Ultrafast Laser is part of Applied Energetics' Wild Cat series of products.  The Leopard is designed and built for the rugged environment of industrial micromachining.


Laser Performance:

• High Output Power: >100 W at 30 MHz, non-CPA operation
• Yb:YAG Thin Disk: 1031 nm wavelength
• High Pulse Energy: >1 mJ/pulse at kHz rep rates
• Pulse Width: <800 femtoseconds up to 10 picoseconds
• Repetition Rate: 1 kHz to 5 MHz with pulse picker
• Selectable harmonics: UV up to 1.03μm (optional)
• System includes on-board stretcher and compressor
• Full diagnostics and instrumentation of system performance

The Leopard Ultrafast Laser from Applied Energetics

UltraFast Laser for Micromachining

The Applied Energetics applications center in Tucson includes a Laser µFAB- a tabletop laser microfabrication workstation. The Laser µFAB is designed for use in laser ablation and surface structuring of tough materials, writing of waveguides and microfluidics. Relevant industrial materials that can be used in ablation applications include metals, polymers, semiconductors, glasses, and ceramics. The 3rd party software GOL3D is used to control the workstation.

Fig. 1 - Laser Microfabrication Workstation

The Applied Energetics WildCat Ultrafast Laser system contains the patented Ocelot oscillator and Leopard Amplifier in an integrated chassis.  The laser outputs over 1 GW peak power at 1 KHz and 800 fs pulse width.  It produces 100W average power at 30 MHz.  The system can be integrated with the laser microfabrication workstation of your choice. The laser works in concert with the microfabrication workstation.

Fig. 2 - WildCat Ultrafast Laser System

For more information on our Applications Center call 480-510-4611

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

The thin disk laser (TDL)

The thin disk laser (TDL) is normally a diode-pumped, high-power, solid-state laser. A thin-disk laser with a multi-pass pumping configuration was first introduced in the 1990’s by the Adolf Giesen group at the University of Stuttgart, Germany.  The thickness of a thin disk laser crystal is typically only a few hundred micrometers.

Figure 1.  The heat sink on the backside of the disk normally uses water to remove heat caused by pumping.  Source: Encyclopedia of Laser Physics and Technology http://www.rp-photonics.com/

                                                                                                                                                                                                                                               

The thickness (100~300 mm) is small compared to the diameters of the pumped area and the laser beam (usually a few millimeters). The disk has a highly reflective coating on one side and an anti-reflective coating on the other side for both pump and laser wavelengths. The reflective side is mounted directly onto a water-cooled heat sink and the disk acts as an active mirror. The thin disk is sometimes called an “active mirror”, because it is like a mirror with laser gain. It can be cooled very efficiently and the heat flow is mainly one-dimensional towards the heat sink, i.e., co-linear with the direction of the laser beam. The thermal gradients in the transverse direction are weak, and thermal lensing is therefore strongly reduced compared to a rod or slab design. Pump absorption in a single pass through the thin disk is low. However, highly efficient operation is achieved by arranging multiple pump passes through the disk (typically 16 to 24 passes).

  Our Applied Energetics “Wild Cat” line of laser amplifiers uses Yb:YAG (Ytterbium-doped yttrium aluminum garnet) thin disk laser (TDL) gain media. Ytterbium (Yb) is a chemical element belonging to the group of rare earth metals (Lanthanides) with atomic number 70.  Ytterbium is often used as a doping material (Yb3⁺) for high powered and wavelength-tunable solid state lasers.

  Ytterbium was discovered by the Swiss chemist Jean Charles Galissard de Marignac in the year 1878 and named it for Ytterby, the Swedish village near where he found the new mineral.

Figure 2.  Atomic energy levels of Yb3+ ions in Yb:YAG, showing the 940nm pump and 1030nm laser transitions.  Source: Encyclopedia of Laser Physics and Technology http://www.rp-photonics.com/

                                             

Ytterbium-doped YAG lases at about 1030 nm, with a broad, 18 nm wide absorption band at 940 nm. The energy levels are of the form ^(2s+1) L_J  such that the ground state manifold ²F_7/2 means that spin quantum number S=1/2, F corresponds to orbital quantum number L=3, and total angular momentum J=7/2. At Applied Energetics, we use InGaAs (Indium gallium arsenide) laser diodes at 940nm to pump our Yb:YAG thin disks.


For more information go to  www.appliedenergetics.com

AE's Ultrafast lasers

AE's Ultrafast lasers

An ultrafast laser emits ultrashort pulses of light, generally on the order of femtoseconds (10 ^{− 15} s) up to picoseconds (10 ^{− 12} s). These lasers are also known as ultrashort pulse (USP) or femtolasers. The 1999 Nobel Prize in Chemistry was awarded to Ahmed Zewail for using ultrashort laser pulses to observe chemical reactions on the timescales they occur on, opening up the field of femtochemistry. Applied Energetics is producing lasers for processes such as micro-machining, micro-drilling, laser-drilling, precision machining, fine cutting, micro-fabrication, and laser ablation. Our Leopard Amplifier is shown below:

High Gain & High Power
Computer Controlled Pulse Repetition Rate (kHz to MHz)
100 W @ 30 MHz (from 20 nJ pulses to 3.3µJ, Gain ~100 )
2 W @ 1 kHz (from 10 nJ pulses to 2 mJ, Gain ~ 100,000 )
Pulse Width< 800fs
Wavelength ~ 1031nm
Yb:YAG Thin Disk gain media

                                                                                                                                                                                   
For more information go to http://www.appliedenergetics.com/

Thank You!

Dr. L

3590 E. Columbia Street
 Tucson, AZ 85714
Dr. Lonnie Lucas
Product Line Manager- Lasers & LGE
llucas@AppliedEnergetics.com

Cell 480.510.4611

Hello and welcome to the AE Ultrafast Lasers blog !!