Data sheet microchip MC-1064-50ps
microchip for pulsed laser emission at a wavelength λ = 1064 nm
MC – Microchip
MC-1064-50ps - microchip with 1064 nm laser emission and 50 ps pulse duration
Table of contents:
1. Microchip description and
applications..........................................................................................
1
2. Microchip parameters
....................................................................................................................
2
3. Microchip laser
setup.....................................................................................................................
4
4. Theoretical considerations about pulse duration, repetition rate and pulse
energy...................... 5
1. Microchip description and applications
The Microchip (MC) consists of a saturable absorber mirror bonded with a Nd:YVO4
laser crystal. The
MC can be used to generate pulsed laser radiation at 1064 nm wavelength if
pumped with a pump
diode at 808 nm. Possible application areas of this laser radiation are:
? micromachining
? light detection and ranging (LIDAR)
? precision measurements
? frequency conversion
The main advantage of a laser build with this microchip is the pump power
dependent repetition rate
with fixed pulse duration and pulse energy. By simply increasing the pump power
at 808 nm the
repetition rate - and consequently the average output power - will be increased
proportionally starting
from the laser threshold.
2. Microchip parameters
Laser emission wavelength λ = 1064 nm
Pump wavelength λ = 808 nm
Pulse duration tP ~ 50 ps
Pulse energy EP ~ 4 nJ at 60 µm pump spot diameter
Repetition rate fR ~ 100 kHz – 3 MHz, dependent on the pump power density
Average output power PAV ~ 0.2 – 10 mW, dependent on the pump power
Pump power density 5 kW/cm
2
(threshold) - 55 kW/cm
2
(maximum)
Beam quality M
2
= 1.05 at 60 µm pump spot diameter
Copper heat sink 12.7 mm diameter, 6 mm thick
microchip is mounted on the centre in a 1 mm deep groove
The average output power P and the repetition frequency fR are a function of the
optical pump power.
These dependencies are nearly linear above the laser threshold. The jitter of
the repetition frequency
decreases with increasing pump power to about 2 %, whereas the pulse energy EP
remains constant.
3. Microchip laser setup
The microchip consists of a saturable absorber mirror (SAM) and a Nd:YVO4 laser
crystal. Because the
SAM is not transparent, the laser setup must be in reflection mode. For optical
pumping a multi-mode
laser diode with about 1 W cw output power at 808 nm wavelength is appropriate.
The proposed laser
setup using two lenses and a dichroic mirror is shown below.
The dichroic mirror has a high reflectance for the laser output at 1064
nm wavelength and a high transmittance for the 808 nm pump light.
The laser output is collimated and nearly diffraction limited, if the
pump spot diameter in the laser crystal of the microchip is small
enough. Typical pump spot diameter values are between 40 µm and
