The quasi two-dimensional geometry of the disk laser results in conceptional advantages over other geometries.
Fundamentally, the thin disk laser allows true power scaling by increasing the pump spot diameter on the disk
while keeping the power density constant. This scaling procedure keeps optical peak intensity, temperature,
stress profile, and optical path differences in the disk nearly unchanged. The required pump beam brightness -
a main cost driver of DPSSL systems - also remains constant.
We present these fundamental concepts and present results in the wide range of multi kW-class CW-sources,
high power Q-switched sources and ultrashort pulsed sources.
Diode-pumped solid-state lasers are gaining acceptance as the desired laser source for materials processing as well as a
host of new applications that are expanding rapidly. Because of this, the performance, stability and lifetime of the diode-pump
source face unprecedented scrutiny. Increasing the lifetime of the diode, while increasing power, remains a
primary focus of the industry. One lifetime limiting issue is that of a voltage potential in the water cooling channels
which can cause cooler degradation and lower efficiency over time. Studies have been carried out that explore different
cooling approaches based on passive schemes where insulation layers are present to shield the voltage from the water
channels. However, with the introduction of insulation layers, a reduction of the deployable power from that of
microchannel coolers is seen. This report explores the effects of passive cooling approaches on the power and
divergence of 1 cm AuSn/CuW mounted bars with fill factors ranging from 10% to 50%. It is shown that a 150 W array
can be realized on a passive cooler and multiplexed to give a 1600 W stack. Thermal modeling is presented along with
life-test data for passively cooled devices.
This paper highlights unique advantages of the disk laser technology for converting the moderate brilliance of laser
diodes into excellent solid state laser beam quality with high efficiency. In contrast to traditional diode pumped
solid state lasers, particularly all relevant fluencies remain constant when the power is scaled by increasing the
active area of the disk. The state of the art TRUMPF disk laser family is presented, including latest results.
Theoretical and practical limits are discussed and an outlook over new disk laser generations including high
power cw, q-switched, and amplified systems is given.
The actin cortex is an adaptive chemo-mechanical polymer network located beneath the cell membrane. A thin, quasi two-dimensional (2D) network, the actin cortex plays a leading role in controlling cellular viscoelasticity, shape, and motility. Regulated by internal and external stimuli, the actin cortex varies its properties with controlled polymerization and depolymerization of actin. For constructing and probing biomimetic actin networks we combined three different techniques to achieve complete spatial, visual and chemical control of the microenvironment: 1) dynamic holographic optical tweezers (HOTs) which produce and independently steer one to hundreds of optical traps, 2) fluorescence microscopy for imaging of actin and 3) a specially-designed microfluidic system, which precisely controls the chemical environment. Using this system, we take two approaches to construct biomimetic 2D actin networks. First HOTs micropattern surfaces with microspheres onto which actin can the be grown. Secondly, HOTs in combination with a multi channel microfluidic system are used to coat optically-trapped microsphere arrays with actin.