TECHNICAL NOTE
Ultrafast Compressor Capabilities
To detect weak spectra in absorption spectroscopy, a common technique
utilizes multipass cells to pass light through a sample multiple times, increasing
the optical path length and amplifying the absorption signal. These multipass
cells, also known as Herriot cells, consist of two concave mirrors, or
a concave and at mirror, with holes that act as entrance and exit apertures
through the cell (Figure 1). This con guration ensures a long optical path
length through increased re ections while being compact and stable to
small perturbations.
This multipass con guration can be customized by Edmund Optics® by applying
the concept to an all-mirror pulse compressor design utilizing dispersive
mirrors. This technique increases the number of re ections while utilizing
only 2 mirrors. Figure 2 illustrates the results of a dispersive mirror with
GDD of -1.000 fs2 and re ectivity of >99,9% between 1010 and 1070 nm.
Adding one or more dispersive mirrors to a multipass cell con guration is
advantageous in building a compact, tunable, and alignment-free ultrafast
compressor. Careful optical design of the system is necessary to obtain a high
quality beam. This compact compressor can be used in a Chirped Pulse Ampli-
cation (CPA) laser system or as dispersion compensation in any ultrafast laser
setup that will allow for careful control and ne tuning of the pulse duration.
Contact Edmund Optics to discuss your ultrafast compressor needs.
7° AOI, s-pol
0
-200
-400
-600
-800
-1000
-1200
1010 1020 1030 1040 1050 1060 1070 1080
GDD (fs2)
Wavelength (nm)
Figure 2. Measured GDD spectrum of the dispersive mirror used in the
compressor cell at 7° AOI, s-pol.
• BBO Crystals for Frequency Conversion of
800 nm and 1030 nm Lasers
• LBO Crystals for Frequency Conversion of
1030 nm and 1064 nm Lasers
• High Damage Thresholds Up to 10 J/cm2 @
1064 nm, 10 ns, 10Hz
Nonlinear Crystals of either β-barium borate (BBO) or
lithium triborate (LBO) are used for frequency conversion
of laser sources. BBO crystals feature thicknesses
from 0.2 mm to 0.5 mm to minimize group velocity
mismatch and are ideal for frequency doubling or
tripling of Ti:Sapphire and Yb:doped laser pulses. The
critical and noncritical phase matching LBO crystals
are ideal for second or third harmonic generation of
Nd:YAG and Yb:doped lasers. Nonlinear Crystals with
20-10 surface quality and λ/10 (LBO) or λ/8 (BBO)
surface atness provide the broad transparency range
and large nonlinear coe cient needed for the harmonic
generation of fundamental laser frequencies.
Each crystal features a protective anti-re ection (AR)
coating that minimizes re ection and limits fogging
from ambient conditions.
0.025
0.02
0.015
0.01
0.005
0
Intensity Before Compressor
Intensity After Compressor
-0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1
Intensity
Time Delay (ps)
Figure 3. Autocorrelation measurement of the laser pulse
duration before and after the compressor. The signal was fi t
using a sech2 function.
Figure 1. A scheme of a multipass cell consisting of two concave
mirrors with through holes.
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Nonlinear Crystals
Dimensional Tolerance (mm): +0,0/-0,1
Thickness Tolerance (mm): +0,0/-0,1
Surface Quality: 20-10
Perpendicularity (arcmin): <5
Parallelism (arcsec): <20
Damage Threshold, Reference: 10J/cm2 @ 1064 nm, 10 ns, 10Hz
Surface Flatness: BBO: λ/8
LBO: λ/10
Confi guration: BBO: Mounted in 25,4 mm Mount
LBO: Unmounted
BBO Nonlinear Crystals
Dimensions (mm) Thickness (mm) Clear Aperture (mm) Design Wavelength (nm) Orientation Θ/φ (°) Typical Applications Stock No. Price
6,0 x 6,0 0,20 5,70 800 44,3/90 THG @ 800 nm, Type I #11-170 €599,00
6,0 x 6,0 0,50 5,70 800 44,3/90 THG @ 800 nm, Type I #11-168 €535,00
6,0 x 6,0 0,50 5,70 800 29,2/90 SHG @ 800 nm, Type I #11-167 €535,00
6,0 x 6,0 0,50 5,70 1030 23,4/90 SHG @ 1030 nm, Type I #11-169 €599,00
6,0 x 6,0 1,00 5,70 800 29,2/90 SHG @ 800 nm, Type I #15-277 €515,00
6,0 x 6,0 1,00 5,70 1030 23,4/90 SHG @ 1030 nm, Type I #15-278 €549,00
10,0 x 10,0 0,50 9,40 800 29,2/90 SHG @ 800 nm, Type I #11-166 €899,00
LBO Nonlinear Crystals
Dimensions (mm) Thickness (mm) Design Wavelength (nm) Orientation Θ/φ (°) Typical Applications Stock No. Price
6,0 x 6,0 0,90 1030 42,2/90 SHG @ 1030 nm, Type I #11-171 €949,00
3,0 x 3,0 10,00 1064 90/0 THG @ 1064 nm, Type II #11-174 €490,00
3,0 x 3,0 15,00 1064 90/11,6 NCPM SHG @ 1064 nm, T=150°C #11-172 €449,00
3,0 x 3,0 15,00 1064 90/13,8 SHG @ 1064 nm, Type I #11-173 €389,00
N
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