II nano-tera.ch
Prof. Ursula Keller (PI) Dr. Bauke Tilma Dr. Matthias Golling Mario Mangold Sandro Link Dominik Waldburger Cesare Alfieri
Vertical integration of ultrafast semiconductor lasers and their applications
Prof. Thomas Südmeyer Dr. Stephane Schilt Dr. Valentin Wittwer Nayara Jornod
Dr. Deran Maas Dr. Thomas Paul
start: Nov 2013
Dr. Jacques Morel Dr. Laurent Devenoges
Dr. Gábor Csúcs
Ultrafast lasers … generate coherent light pulses with pico- or femtosecond duration access ultrashort time scales
observe and use fast dynamics • understand chemical reaction dynamics • fast communication • …
pump-probe
optical clocking
2
a)
Ultrafast lasers … generate coherent light pulses with pico- or femtosecond duration access ultrashort time scales
observe and use fast dynamics • understand chemical reaction dynamics • fast communication • …
concentrate in time and space
achieve extremely high intensities • material processing • multi-photon biomedical imaging 30 µm a) b) • …
Brain Research Institute Prof. Fritjof Helmchen Fabian Voigt
pollen grains
30 µm b)
50 µm
c)
brain tissue of mouse
50 µm
3
Ultrafast lasers … generate coherent light pulses with pico- or femtosecond duration access ultrashort time scales
concentrate in time and space
observe and use fast dynamics • understand chemical reaction dynamics • fast communication • … achieve extremely high intensities • material processing • multi-photon biomedical imaging • …
intensity
broad optical spectrum
frequency
generate ultrastable frequency combs • high precision spectroscopy • optical clocks • … 4
MIXSEL II
!
Frequency combs
Multiphoton microscopy
Spectroscopy
Metrology applications
Product development
MIXSEL prototype 5
Ultrafast semiconductor lasers: our approach and goals gain • completely fabricated at ETH Zürich • very compact lasers
loss
few µm few µ
m
• waver-scale production • cost efficient
6
Ultrafast semiconductor lasers: our approach and goals intensity
gain time
VECSEL Vertical External Cavity Surface Emitting Laser
7
Ultrafast semiconductor lasers: our approach and goals gain loss SESAM
VECSEL Vertical External Cavity Surface Emitting Laser
+
Semiconductor Saturable Absorber Mirror
8
Ultrafast semiconductor lasers: our approach and goals VECSEL gain chip
Vertical External Cavity Surface Emitting Laser
+
n ct io se
AR
re gi on ga in
BR D m
SESAM
VECSEL
bo tto
loss
he at si nk
gain
Semiconductor Saturable Absorber Mirror
9
Ultrafast semiconductor lasers: our approach and goals VECSEL gain chip
Semiconductor Saturable Absorber Mirror
n ct io se
AR
re gi on ga in
D m
ab so AR rbe r se ct io n
m tto bo
bs
tra
D BR
te
SESAM
su
+
bo tto
SESAM
VECSEL Vertical External Cavity Surface Emitting Laser
he at si nk
loss
BR
gain
10
Ultrafast semiconductor lasers: our approach and goals gain loss SESAM
VECSEL Vertical External Cavity Surface Emitting Laser
+
Semiconductor Saturable Absorber Mirror
MIXSEL
=
Modelocked Integrated External-Cavity Surface Emitting Laser
11
Ultrafast semiconductor lasers: our approach and goals gain loss SESAM
=
Semiconductor Saturable Absorber Mirror
Modelocked Integrated External-Cavity Surface Emitting Laser
s pu orb m er p D BR ga in re gi on AR se ct io n
ab
rD
BR
MIXSEL chip
se
+
la
Vertical External Cavity Surface Emitting Laser
MIXSEL
he at si nk
VECSEL
12
Targeted laser performance Average output power
10 W
Goal:
1 W
• ultra short pulses ≤ 100 fs 100 mW
• several hundreds mW average output power
10 mW VECSEL
MIXSEL
1 mW 100 fs
1 ps Pulse duration
13
Targeted laser performance Average output power
10 W
Goal:
1 W
• ultra short pulses ≤ 100 fs 100 mW
• several hundreds mW average output power
10 mW VECSEL
MIXSEL
1 mW 100 fs
1 ps Pulse duration
For example for supercontinuum generation for stabilized optical frequency combs
applications for optical frequency combs • • • •
coherent communication spectroscopy optical clocks comb metrology
14
Frequency combs from modelocked lasers I(w)
train of evenly spaced pulses
equidistant frequency comb
frep
E(t) t
FT
w
1 / frep
15
Frequency combs from modelocked lasers I(w)
train of evenly spaced pulses
equidistant frequency comb
frep
E(t) t
FT
w
1 / frep
Optical Frequency Combs
intensity
frep fCEO
fn = m frep + fCEO CEO: carrier envelope offset
frequency Telle, et al., Appl. Phys. B 69, 327 (1999) Diddams, et al., Phys. Rev. Lett. 84, 5102 (2000) 16
Frequency combs from modelocked lasers I(w)
train of evenly spaced pulses
equidistant frequency comb
frep
E(t) t
FT
w
1 / frep
Optical Frequency Combs undefined, optical intensity intensity frequency
phase-stable link: optical to microwave
beat
THz
MHz frequency frequency
Telle, et al., Appl. Phys. B 69, 327 (1999) Diddams, et al., Phys. Rev. Lett. 84, 5102 (2000) 17
Targeted laser performance Average output power
10 W
Goal:
1 W
• ultra short pulses ≤ 100 fs 100 mW
• several hundreds mW average output power
10 mW VECSEL
MIXSEL
1 mW 100 fs
1 ps Pulse duration
optical frequency combs
required: • very broad optical spectrum: supercontinuum • detection of fCEO
octave-spanning & coherent υ
18
Supercontinuum generation and CEO detection Average output power
10 W
1 W
100 mW
10 mW VECSEL
MIXSEL
pulse duration: average output power: repetition rate: center wavelength:
231 fs 100 mW 1.75 GHz 1038 nm
1 mW 100 fs
1 ps Pulse duration
C. A. Zaugg, A. Klenner, M. Mangold, A. S. Mayer, S. M. Link, F. Emaury, M. Golling, E. Gini, C. J. Saraceno, B. W. Tilma, U. Keller, Optics Express, vol. 22, No. 13, pp. 16445-16455, 2014 19
Supercontinuum generation and CEO detection Average output power
10 W
1 W
amplification in Yb-doped fiber amplifier 100 mW
10 mW VECSEL
MIXSEL
1 mW 100 fs
1 ps Pulse duration
C. A. Zaugg, A. Klenner, M. Mangold, A. S. Mayer, S. M. Link, F. Emaury, M. Golling, E. Gini, C. J. Saraceno, B. W. Tilma, U. Keller, Optics Express, vol. 22, No. 13, pp. 16445-16455, 2014 20
Supercontinuum generation and CEO detection Average output power
10 W
1 W
pulse compression in LMA fiber 100 mW
10 mW VECSEL
MIXSEL
1 mW 100 fs
1 ps Pulse duration
C. A. Zaugg, A. Klenner, M. Mangold, A. S. Mayer, S. M. Link, F. Emaury, M. Golling, E. Gini, C. J. Saraceno, B. W. Tilma, U. Keller, Optics Express, vol. 22, No. 13, pp. 16445-16455, 2014 21
Supercontinuum generation and CEO detection Average output power
10 W
[1] H. R. Telle, G. Steinmeyer, A. E. Dunlop, J. Stenger, D. H. Sutter and U. Keller, Applied Physics B 69, 327 (1999)
1 W
coherent supercontinuum generation in nonlinear fiber
100 mW
10 mW VECSEL
MIXSEL
1 mW 100 fs
1 ps Pulse duration
supercontinuum
[1]
C. A. Zaugg, A. Klenner, M. Mangold, A. S. Mayer, S. M. Link, F. Emaury, M. Golling, E. Gini, C. J. Saraceno, B. W. Tilma, U. Keller, Optics Express, vol. 22, No. 13, pp. 16445-16455, 2014 22
Supercontinuum generation and CEO detection Average output power
10 W
[1] H. R. Telle, G. Steinmeyer, A. E. Dunlop, J. Stenger, D. H. Sutter and U. Keller, Applied Physics B 69, 327 (1999)
1 W
coherent supercontinuum generation in nonlinear fiber
100 mW
10 mW VECSEL
MIXSEL
1 mW 100 fs
1 ps
RBW 100 kHz fCEO 1
-25 -50
frep=1.75 GHz fCEO 2
fCEO detection
frep
intensity
int. (dBc)
Pulse duration
fCEO
-75
-100
frequency 0.0
0.5 1.0 1.5 frequency (GHz)
[1]
C. A. Zaugg, A. Klenner, M. Mangold, A. S. Mayer, S. M. Link, F. Emaury, M. Golling, E. Gini, C. J. Saraceno, B. W. Tilma, U. Keller, Optics Express, vol. 22, No. 13, pp. 16445-16455, 2014 23
Supercontinuum generation and CEO detection Average output power
10 W
1 W
100 mW
10 mW VECSEL
MIXSEL
1 mW 100 fs
1 ps Pulse duration
goal: improve performance of the lasers further to get rid of amplification and compression stage
C. A. Zaugg, A. Klenner, M. Mangold, A. S. Mayer, S. M. Link, F. Emaury, M. Golling, E. Gini, C. J. Saraceno, B. W. Tilma, U. Keller, Optics Express, vol. 22, No. 13, pp. 16445-16455, 2014 24
147-fs high-power ultrafast VECSEL Average output power
10 W
1 W
100 mW
10 mW VECSEL
MIXSEL
1 mW 100 fs
1 ps Pulse duration
25
147-fs high-power ultrafast VECSEL Average output power
10 W
1 W
100 mW
10 mW VECSEL
MIXSEL
1 mW 100 fs
1 ps Pulse duration
shortest pulse duration from a highpower ultrafast SDL
pulse duration: average output power: repetition rate: peak power:
147 fs 100 mW 1.82 GHz 328 W
D. Waldburger, M. Mangold, S. M. Link, M. Golling, E. Gini, B. W. Tilma, U. Keller, accepted at CLEO US 2015 26
Shortest pulses of a MIXSEL Average output power
10 W
1 W
100 mW
10 mW VECSEL
MIXSEL
1 mW 100 fs
1 ps Pulse duration
M. Mangold, D. Waldburger, S. M. Link, M. Golling, E. Gini, B. W. Tilma, U. Keller, accepted at CLEO/Europe 2015 27
Shortest pulses of a MIXSEL Average output power
10 W
1 W
100 mW
10 mW VECSEL
MIXSEL
1 mW 100 fs
1 ps Pulse duration
pulse duration: average output power: repetition rate: center wavelength:
253 fs 235 mW 3.35 GHz 1044 nm
cavity length: 44.7 mm
shortest pulse duration from a MIXSEL
M. Mangold, D. Waldburger, S. M. Link, M. Golling, E. Gini, B. W. Tilma, U. Keller, accepted at CLEO/Europe 2015 28
Fiber dispersion modelling supercontinuum generation 1 W
100 mW
10 mW VECSEL
MIXSEL
1 mW 100 fs
1 ps Pulse duration
SEM image of fiber
spectrum
Average output power
10 W
simulated dispersion wavelength [nm]
29
Prototypes for noise characterization 2 VECSEL prototypes
19 cm
25 cm !
noise characterization frequency stabilization
30
2 Photon-microscopy 30 µm
Brain tissue b)of a mouse
a)
50 µm c)
Pollen grains Brain Research Institute Prof. Fritjof Helmchen Fabian Voigt
50 µm
30 µm a)
b)
31
Application: Dual-comb spectroscopy 1.0
requirement: 2 modelocked lasers with slightly different pulse repetition frequencies
0.5 0.0
309.62 optical frequency [THz]
gas cell
MIXSEL 1
signal [arb. u.]
signal [arb. u.]
possible gas spectroscopy setup
1.0 0.5 0.0
detector signal processing
1.0 0.5
309.62 optical frequency [THz]
1.0 0.5 0.0
750 800 850 radiofrequency [MHz]
3 HITRAN:C2H2 2.5
Acetylene has strong absorption lines in the near infrared around 1035 nm.
absorption absorption[%] (%)
0.0
signal [arb. u.]
MIXSEL 2
signal [arb. u.]
309.62 optical frequency [THz]
2
1.5
1
0.5
0 1010
1015
1020
1025
1030
1035
1040
1045
1050
wavelength (nm)
wavelength [nm] 32
Dual-comb MIXSEL heatsink
MIXSEL chip
etalon OC
33
Dual-comb MIXSEL heatsink
MIXSEL chip
birefringent crystal etalon OC
210 µm 220 µm
MIXSEL
p-pol beam
s-pol beam 220 µm
34
Dual-comb MIXSEL heatsink
MIXSEL chip
birefringent crystal
Two pulsed lasers from one MIXSEL chip
50:50 BS etalon OC
8
80 nm multimode pump up to 60 W, M2≈ 36
35
Dual-comb MIXSEL
50:50 BS etalon OC
8 80 nm multimode pump up to 60 W, M2≈ 36
1.0
0.8
λc = 966.11 nm Δλ = 0.25 nm
0.6 0.4 0.2 0.0
0.8 0.6
966.0 967.0 wavelength [nm] meas
τp = 13.5 ps
sech
2
fit
0.4 0.2 0.0 -40 0 40 delay [ps]
output power [mW] pulse repetition frequency [GHz]
spectral intensity [arb. u.]
birefringent crystal
1.0
1.0
autocorrelation [arb. u.]
MIXSEL chip
spectral intensity [arb. u.]
heatsink
autocorrelation [arb. u.]
s-polarized beam p-polarized beam
1.0
λc = 966.01 nm
0.8 Δλ =
0.6 0.23 nm 0.4 0.2 0.0
966.0 967.0 wavelength [nm] meas
0.8
sech fit
0.6
2
τp = 19.1 ps
0.4 0.2 0.0
-40 0 40 delay [ps]
s-pol
p-pol
76
70
1.895
1.890
36
Dual-comb MIXSEL
50:50 BS etalon OC
8 80 nm multimode pump up to 60 W, M2≈ 36
amplitude [dBc]
microwave comb 0
comb1
span 150 MHz RBW 1 kHz
-10
Δλ = 0.25 nm
0.6 0.4 0.2 0.0
0.8 0.6
966.0 967.0 wavelength [nm] meas
τp = 13.5 ps
sech
2
fit
0.4 0.2 0.0 -40 0 40 delay [ps]
output power [mW]
-20 0.44
1.0
0.8
λc = 966.11 nm
0.48
0.52 frequency [GHz]
0.56
pulse repetition frequency [GHz]
spectral intensity [arb. u.]
birefringent crystal
1.0
1.0
autocorrelation [arb. u.]
MIXSEL chip
spectral intensity [arb. u.]
heatsink
autocorrelation [arb. u.]
s-polarized beam p-polarized beam
1.0
λc = 966.01 nm
0.8 Δλ =
0.6 0.23 nm 0.4 0.2 0.0
966.0 967.0 wavelength [nm] meas
0.8
sech fit
0.6
2
τp = 19.1 ps
0.4 0.2 0.0
-40 0 40 delay [ps]
s-pol
p-pol
76
70
1.895
1.890
à direct link between the terahertz frequencies and the electronically accessible microwave regime S. M. Link, A. Klenner, M. Mangold, C. A. Zaugg, M. Golling, B. W. Tilma, U. Keller, Optics Express, vol. 23, No. 5, pp. 5521-5531, 2015 37
Dual-comb MIXSEL
50:50 BS etalon OC
8 80 nm multimode pump up to 60 W, M2≈ 36
amplitude [dBc]
microwave comb 0
comb1
span 150 MHz RBW 1 kHz
-10
Δλ = 0.25 nm
0.6 0.4 0.2 0.0
0.8 0.6
966.0 967.0 wavelength [nm] meas
τp = 13.5 ps
sech
2
fit
0.4 0.2 0.0 -40 0 40 delay [ps]
output power [mW]
-20 0.44
1.0
0.8
λc = 966.11 nm
0.48
0.52 frequency [GHz]
0.56
pulse repetition frequency [GHz]
spectral intensity [arb. u.]
birefringent crystal
1.0
1.0
autocorrelation [arb. u.]
MIXSEL chip
spectral intensity [arb. u.]
heatsink
autocorrelation [arb. u.]
s-polarized beam p-polarized beam
1.0
λc = 966.01 nm
0.8 Δλ =
0.6 0.23 nm 0.4 0.2 0.0
966.0 967.0 wavelength [nm] meas
0.8
sech fit
0.6
2
τp = 19.1 ps
0.4 0.2 0.0
-40 0 40 delay [ps]
s-pol
p-pol
76
70
1.895
1.890
Swiss patent application 01498/14, filed 2 October 2014 S. M. Link, A. Klenner, M. Mangold, C. A. Zaugg, M. Golling, B. W. Tilma, U. Keller, Optics Express, vol. 23, No. 5, pp. 5521-5531, 2015 38
MIXSEL II
!
Frequency combs
Multiphoton microscopy
Spectroscopy
Metrology applications
Product development
MIXSEL prototype 39
MIXSEL II
!
Frequency combs
Multiphoton microscopy
Average output power
10 W
1 W
100 mW
10 mW VECSEL
MIXSEL
1 mW 100 fs
1 ps Pulse duration
Spectroscopy
Metrology applications
Product development
MIXSEL prototype 40
MIXSEL II
!
Frequency combs
Multiphoton microscopy
Average output power
10 W
1 W
100 mW
10 mW VECSEL
MIXSEL
1 mW 100 fs
1 ps Pulse duration
Spectroscopy
Metrology applications
Product development
MIXSEL prototype 41
MIXSEL II
Frequency combs
b)
Multiphoton microscopy
10 W Average output power
!
50 µm
30 µm a)
1 W
50 µm
100 mW
c)
10 mW VECSEL
MIXSEL
1 mW 100 fs
1 ps Pulse duration
Spectroscopy
Metrology applications
Product development
MIXSEL prototype 42
MIXSEL II
Frequency combs
b)
Multiphoton microscopy
10 W
heatsink
1 W
50 µm
100 mW
c)
MIXSEL chip
birefringent crystal
50:50 BS etalon OC
10 mW
8
80 nm
Average output power
!
50 µm
30 µm a)
VECSEL
MIXSEL
1 mW 100 fs
multimode pump up to 60 W, M2≈ 36
1 ps Pulse duration
Spectroscopy
Metrology applications
Product development
MIXSEL prototype 43
MIXSEL II
!
Frequency combs
Multiphoton microscopy
Spectroscopy
Metrology applications
Product development
MIXSEL prototype 44