Kansas Light Source
Laser System
J. R. Macdonald Laboratory
Department of Physics, Kansas State University
September, 2010
Kansas Light Source:
Amplified Ti:Sapphire Laser System
F eedbac k loop to stabilize CE P
C oline a r f -2f
T i: sa p ph ire o sc ill ato r
in ter fe ro m ete r
S tre tch e r
P um p la ser
P um p la se r
T iS c ry sta l
N on c olin e ar f- 2f
in ter fe ro m ete r
Amplifier
C om p re sso r
N e ga s f ille d ho llo w f ib er
Be a m sp litte r
( L=1 m )
FR O G
C h ir p m irr or c om p re ssor e
P ow er m e te r
S pe c tr om e ter
Be a m sp litte r
KLS output
Mode-Locked
Ti:Sapphire Oscillator
Multi-pass
Ti:Sapphire Amplifier
350 mW Average Power
12 fs Pulse Width
80 MHz Repetition Rate
5 nJ Pulse Energy
800 nm Central Wavelength
95 nm Bandwidth
4 W Average Power
27 fs Pulse Width
2 KHz Repetition Rate
2 mJ Pulse Energy
780 nm Central Wavelength
40 nm Bandwidth
Light Amplification by Stimulated Emission of Radiation
Light Amplification by Stimulated Emission of Radiation
Pump
Cavity mirror
Cavity mirror/output coupler
Laser medium
Laser output
Optical cavity→ LASER
Interaction of light with matter
In laser medium
Absorption
Spontaneous
emission
Stimulated
emission
Population inversion → LASER
Ti:Sapphire crystal
Ti3+:Al2O3
Chirped Pulse Amplification
Mode-locked oscillator
KLS oscillator -- FemtoLaser
Pump verdi
M-1
Ti:S
M5 Lens
Horizontal polarization
from oscillator
M0
M1
M7
M6
M3
M2
M4E
M9
To stretcher
and amplifier
M8
OC CP
M4
M11
M12
M13
Power meter and
spectrometer
To f to 2f system
M10
Note:
M7, M8, M12 and M13 mirrors are chirped mirrors.
M-1,M9 and M10 are periscopes.
A 50% beam splitter in M9.
CPA stretcher/compressor
Positive
Dispersion
Negative
Dispersion
KLS stretcher
KLS Multi-Pass Amplifier
KLS Multi-Pass Amplifier
FROG: Beam Diagnostic
BBO
Infrared
Filter
M6
Translation
Stage
spectrometer
M3
M5
M2
M4
From Laser
M1
BS
I1(t)
I2(t)

k1

k2
KLS system
KLS system timing
Delay
Generator
CEP
Control
Menlo
System
Pump1
2 kHz
SRS 645
80 MHz
Oscillator
Pump2
PC1
PC2
PD1
PC1
PC2
PD2
PD3
PD4
Oscilloscope
KLS subsystems and devices
Oscillator: pump laser, crystal chiller, photo diode, Menlo timing controller
Amplifier: crystal chamber and vacuum pump, liquid nitrogen controller,
Dewar, delay generator, pockels cells, pockels cell power supplies, pump
lasers, pump laser power supplies, pump laser control computers, pump laser
chillers, photo diodes, oscilloscope, power meter, power monitor, power
locking PID (proportional–integral–derivative) controller, spectrometer,
spectrometer computer
FROG: spectrometer, spectrometer computer, CCD camera, FROG computer
Other: power meters, mobile spectrometer, IR viewer, IR cards
Optics
Coated Mirrors (metal or dielectric): reflectivity, phase, bandwidth,
damage threshold
Beamsplitters: dielectric coating, reflectivity and transmission,
phase, bandwidth, damage threshold
Lens and windows: coating, material, thickness
Wave plates: coating, material, thickness
Polarizer
Chirped mirror and compensation plates
Gratings and prisms
Nonlinear optical crystals
Safety
Wear your goggles
Know where the beam goes
Do not put your eyes at the beam height
Contact
Kun Zhao (Harry)
Baozhen Zhao
Al Rankin
Well, let’s see some real stuff now
Spectrum, Dispersion, Chromatic Aberration
Chromatic and Astigmatism Aberrations
Of a Lens
Birefringence and Wave Plate
Half-wave plate
Polarization, s or p
Energy, Power, Spectrum
IRIS4
Polarizer
Half wave plate
Horizontal
Linear
Horizontal+45degree
Fara
To amplifier
Sm2
Polarizer
Sm3
IRIS3
Photodiode
Femtolaser
oscillator
Horizontal
M9
Half wave
plate Polarizer
IRIS2
Horizontal
Sc2
Sc1
Pokcel cell
M10
To f-2f system
Photodiode
Polarizer
Sm4
Flip Half wave
plate
Sm1
Sg2
IRIS1
Sg1
Monitor
Power meter
Powermeter
Photodiode14
M13
Photodiode3-7
M8
First pass
M7
Photodiode1
Second pass
M2
M12
M9
M10
Third pass
M3 M1
Fourth pass
M4
CCD
Fifth pass
Photodiode2
Sixth pass
Pump1
M11
M5
M6
Pump2
Seventh pass

Stretcher
CEP Lock
PC1
2
Seed
Femtolaser
oscillator
Verdi-6

Evolution 30
Pump
Pump
Evolution 30

2
2
Amplifier
PC2
Compressor

2
Final Output
5µs
CE
Control
System
Timer
f/16
2V
Menlo
System
BNC 555A
f/45
Channel
Timer
BNC 555B
A
Pump1380
B
Pump2302
C
PC11900
D
PC21940
10ns
75 MHz, 1V
f/
4
Oscillator
1.5 V, jitter 1 ns
to Experiment
PD1
KLS Timing
CE measure
PC1
Pulse
Generator
Philips PM5712
Jan 15, 2005
PC2
PD2
PD3
75M-1kHz
1 kHz
400 mV
150 mV
PD4
1 kHz, 1V
Oscilloscope
Tek TDS3054
Laser Metrics 5046
INPUT
7.5 kV
Trig
INPUT
HV Adj
HV
Q-SW
Laser Metrics 5046
Bias
76 MHz
Q-SW
Width
MON
Outputs
Delay
Photo
Diode
OUT
Trig
Pockels
Cell 1
kHz
Master kHz signal is generated by DG535. PC1
is trigged by the kHz laser signal selected by
the master signal and the signal from the photo
diode. PC2 is trigged by the MON signal from
PC1. Long cables are used for PC1 to
compensate the trig delay of PC2
0
AB
Bias
CW
Delay
Width
Long cable
delay goes to
control room
MON
Outputs
Pockels
Cell 2
DG535
DG535
IN
HV Adj
HV
CW
Delay
7.5 kV
CD
Pump1: A: 510 ns; B: A + 5 s
Pump2: C: 310 ns; D: C + 5 s
Delay Unit: > 1 us
PC1: Delay 55 ns; Width 10 ns
PC2: Delay 45 ns; Width 10 ns
Pump1 Pump2