Mixsel2

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