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Laser & Fiber Electronics Group
Institute of Telecommunications, Teleinformatics and Acoustics
Wrocław University of Technology
Group members
• Head: Professor Krzysztof M. Abramski
• Staff: • Dr. Arkadiusz Antończak • Dr. Paweł Kaczmarek • Dr. Adam Wąż • Dr. Grzegorz Dudzik • Dr. Michał Nikodem (on leave to Princeton University, Department Of
Electronics)
• PhD students: • Jarosław Sotor• Maciej Nowak• Grzegorz Soboń• Paweł Kozioł • Karol Krzempek• Rafał Lewicki (on leave to Rice University, Laser Science Group)• Natalia Trela (on leave to Heriott-Watt University, Laser and Photonics
Applications Group)
• 12 MSc students
Our research
1. Fiber lasers and amplifiers:• MOPA systems• Optical frequency combs
2. Solid state diode pumped single frequency microchip lasers
3. Laser micromachining 4. Laser-fiber vibrometry
2-stage All-Fiber MOPA setup
P. Kaczmarek, G. Soboń, A. Antończak, J. Sotor, K.M. Abramski, „Fiber-MOPA sources of coherent radiation”, Bulletin of The Polish Academy of Sciences, Vol. 56, Issue 4 (2010)
~37 dB gain 1540-1570 nm 4.8 W output power (ŋ = 24%)
Output signals (SNR > 50 dB)Experimental setup
Features:
Dual-stage all-in-fiber MOPA system
4.8 W output power (CW mode)
1550 nm eye-safe region
Signle-frequency tunable (1540 – 1570 nm)
potential source for nonlinear frequency conversion, Tm3+ laser and amplifier pumping
Self-made additional equipment
Water-cooler Laser Diode Temperature Controller
Cooling blocks for 3*10W diodes High Power Laser Diode Temperature Controller
2-stage MOPA – pulsed regime
Power Amplifier
Output
Pre-amplifier
Pulse-shaping effect
G. Sobon, P. Kaczmarek, A. Antonczak, J. Sotor, A. Waz, K.M. Abramski, „Pulsed Fiber-MOPA source operating at 1550 nm with pulse distortion pre-compensation”, Optical Fiber Communication Conference and Exposition OFC 2011 paper- in review
Pulse distortion
8 ns output pulse Peak power vs. Repetition rate
Features:
8 ns pulses
tunable repetition rate (> 10 kHz)
Pulse-shaping system (pulse distortion pre-compensation)
100 ns flat-top pulses with high energy
potential source for military, LIDAR, free-space telecom, etc.
3-stage Fiber-MOPA system
IsolatorWDM
Coupler
Er3+ doped fiber
Isolator99/1%
Coupler
DFB seed 1550 nm
Pump Combiner
99.9/0.1% Coupler
Output
WDM Coupler
Mode-stripper
Isolator
1% 1%
0,1%
99,9%
FC/APC High-powerPump
Combiner
Pump LDs λ = 915 nm, P = 35W Double-Clad LMA
Er3+/Yb3+ (15 m)
Isolator
Mode-stripper
Pump LDs λ = 980 nmP = 750 mW
Back-scattered light monitor
1st stage output power monitor
Double-Clad Er3+/Yb3+ doped
fiberPump LDs λ = 975 nm
P = 10 W
2nd stage output power monitor
Passive DC LMA
Taper splices
35W diodes Pump injection system LMA Fiber Tapered splice
Features:
All-in-fiber design
Large Mode Area (LMA) Erbium-Ytterbium fiber used (25 μm core diameter)
6 * 35W pumping power (915 nm)
High output power expected (~20W)
Cladding mode-stripper
169 MHz repetition rate, passively mode locked fiber laser
Features:
nonlinear polarization rotation operation principal
169 MHz fundamental repetition rate
1,2m of cavity length (30cm of Er3+ fiber)
111 fs pulses
30 mW of average output power
1550nm working wavelength (Eye-safe region)
Michał Nikodem, Krzysztof Abramski, „169 MHz repetition frequency all-fiber passively mode-locked Erbium doped fiber laser,” Optics Communications 283, 109-112 (2010).
Michał Nikodem, Grazyna Tomczyk, Aleksander Budnicki, Krzysztof Abramski, „Investigation of passively mode-locked erbium doped fiber ring laser due to nonlinear polarization rotation,” Opto-electronics Review, Vol. 16, No.2, 123-127 (2008).
Optical frequency comb stabilization
Michał Nikodem, Krzysztof Abramski, „Controlling the frequency of the Frequency Shifted Feedback fiber laser using injection-seeding technique,” Optics Communications 283 (2010), pp. 2202-2205.
Michał Nikodem, Ewelina Kluzniak, Krzysztof Abramski, „Wavelength tunability and pulse duration control in frequency shifted feedback Er-doped fiber lasers,” Optics Express 17, 3299-3304 (2009).
Long-term frequency fluctuations less than 0,93 MHz
Single frequency Nd:YAG/KTP laser
22 ln
cFSR
where:Δn = 0,0844 – is the natural birefringence of KTP (nz - ny), l2 – geometrical length of KTP
mm11n
cl
G
22
L0
l1
Nd:YAG KTP
HR@1064nmAR@532nm
AR@808nmHR@1064nm & 532nm
Brewster plate
P0, 0
532 nm
1064 nm
l2
LOSS@1064nm
FSR
Antończak Arkadiusz, Sotor Jarosław, Abramski Krzysztof: Single frequency green laser with birefringent filter. W: Proceedings of 2006 8th International Conference on Transparent Optical Networks with 5th European Symposium on Photonic Crystals.., Nottingham, UK, June 18-22, 2006. Vol. 4 / [Ed. M. Marciniak]. Piscataway, NJ : IEEE, cop. 2006.pp. 178-180
Single frequency Nd:YAG/KTP laser
single frequency / TEM00 mode operation,
output power (at pumping power: P808 = 1W):> 50mW @ 532nm~ 4mW @ 1064nm
110GHz frequency tune:
∆ν0 ~ 110GHz@1064nm(220GHz@532nm)
Antończak Arkadiusz, Sotor Jarosław, Abramski Krzysztof: Single frequency microchip solid state diode pumped lasers. Bulletin of the Polish Academy of Sciences. Technical Sciences. 2008, vol. 56, nr 2, s. 113-116
Nd:YAG/BIBO – 473nm for underwater vibrometry
output power @P808 = 1W~ 20mW @ 473nm
good beam quality - TEM00
Antończak Arkadiusz, Sotor Jarosław, Matysiak Mateusz, Abramski Krzysztof: Blue 473-nm solid state diode pumped Nd: YAG/BiB0 microchip laser. Opto-Electronics Review, 2010, vol. 18, nr 1, pp. 71-74,
Microchip laser stabilized by fiber Bragg grating
0 15 30 45 60
Tem perature [°C ]
1063.60
1063.80
1064.00
Wav
elen
gth
[n
m]
m easured point
polynom ial fit
non-atherm al package
Differential Amplifier & PID
Radiator
Nd:YAG/ KTP1064nm&532nm
Dichroic mirror
1064nm
PIN-diode(transmited signal)
Thermoelectric cooler
Stabilized laser
PIN-diode(reflected signal)
Athermal housedFBG @1064nm
532nm
Fibre Coupler 50:50%
Power Amplifier
Temperature Controller of the
Fibre Bragg Grating
Power Supply &Temperature
Controller of the LD
(VOA)
IsolatorTo Optical Spectrum Analyser
frequency stability at the level of 10-7, simple frequency stabilization ofthe laser for metrological purposes.
1063.79 1063.81 1063.83 1063.85
W avelength [nm ]
-100.0
-90.0
-80.0
-70.0P
ower
leve
l [dB
m]
10°C
15°C
20°C
25°C
35°C
45°C
55°C
ΔλΔλmm = 0,35pm/ = 0,35pm/ooC => C => ((93MHz/93MHz/ooC)C)
Antończak Arkadiusz, Sotor Jarosław, Abramski Krzysztof: Single frequency solid state laser stabilized by FBG. W: Proceedings of 2008 10th Anniversary International Conference on Transparent Optical Networks with 7th European Symposium on Photonic Crystals, Athens, Greece, June 22-26, 2008.
Fast Frequency Control of Microchip Lasers
HVamplifierHSA - 01
CurrentamplifierTA - 01
300Vpp
RF amplifierB = 300MHz
SR 445
Spectrumanalyser
HP 8592L
Programmablecounter
PFL - 32
PLL
TLC2932
Ku=25V/V
PIN diode (Hamamatsu)G8376-01
Pump: 808nm 400mW
Thermo-ElectricCooler
Radiator
LL - 02CC 1064
Power supplyMPL 2500
LiNbO3Nd:YAG
Reference compact laser(thermally controled)
Slave laser(electrooptically controled)
LP filter 1
LP filter 2Variableattenuator0 - 100dB
1E -5 1E -4 1E-3 0.01 0.1 1 10 1E+2Averaging tim e [s ]
0.1
1
10
1E+2
1E+3
1E+4
1E +5
1E+6
1E +7
1E+8
Squ
are
root
of A
llan
Var
ianc
e
[H
z]
w ithout stab ilisation
0 100 200 300T im e t [s ]
0
100
200
300
Offs
et fr
eque
ncy
[MH
z]
Free running case
w ithout stab ilisation
w ith stab ilisation TEC + EO M (= 0,68 m s)
Free running case
EO M + TEC stabilisation
1 0 H z
fm = 1kHz fm = 5kHz fm = 10kHz fm = 50kHz
fm = 100kHz fm = 500kHz fm = 800kHz fm = 1,5MHz
Sensitivity X: 5MHz/div, Y: 10dB/div, Ref: -20dBm, UEOM = 10 Vpp
Antończak Arkadiusz, Abramski Krzysztof: Frequency control of microchip lasers. W: Joint Conference of the German Society of Applied Optics (DGaO) and the Section of Optics of the Polish Physical Society. 106th Conference of the DGaO, Wrocław, 17-20 May, 2005, Deutsche Gesallschaft fur Angewandte Optik,
Single frequency green (532nm) laser with YVO4 beam displacer -
conception
o-ray
e-ray
YVO4 optical axis plane2m
m
5mm
0.5m
m
L0= 16mm
l1
Nd:YVO4
KTPYVO4 (walk-off)
l2
LOSS - opposite polarization
P0, 0
532 nm
1064 nm
l3
LOSS - Lyot filter
Crystals cutting and single frequency laser configuration with YVO4 beam displacer
J.Z. Sotor, A.J. Antończak, K.M. Abramski, “Single-longitudinal mode Nd:YVO4/YVO4/KTP green solid state laser,” Opto−Electronics Review 18(1), 75–79,(2010),
J.Z. Sotor, A.J. Antończak, K.M. Abramski, „Single frequency, monolithic solid state laser”, Patent application, P383937, 02.07.2009.
Features:
• birefringent filter formed by YVO4 beam displacer and KTP crystal,•possibility of monolithic realization,•resistant to environmental hazards.
Monolithic single frequency laser
Designed and manufactured monolithic laser resonator consist of three crystals bonded together with UV adhesive. Total resonator dimension:• 2x2x10.5mm,• 1x1x10.5mm (extended single frequency operation range)
J.Z. Sotor, G. Dudzik, A.J. Antończak, K.M. Abramski, “Single-longitudinal mode, monolithic, green solid-state laser”, Applied Physics B, (2010), revised and accepted,J.Z. Sotor, A.J. Antończak, K.M. Abramski, „Single frequency, monolithic green DPSS laser”, Photonics West 2010, SPIE, Vol. 7578, 75782J (2010).
Practical realization of single frequency DPSS laser
Experimental set-up of single frequency DPSS laser
Monolithic single frequency laser – parameters
Features:• single frequency operation temperature range with mode hopping (Fig.a),• output power @532nm up to 160mW (Fig.b),• output power stability ±0.75% (Fig.c),• long term frequency stability 3·10-8 (Fig.d),• Gaussian beam profile with M2 at the level of 1.2
a) b) c)
d)
J.Z. Sotor, A.J. Antończak, K.M. Abramski, Single-longitudinal mode miniature, green solid state laser, Europhoton 2010, Hamburg 29.08–3.09.2010J.Z. Sotor, A.J. Antończak, K.M. Abramski, Single frequency monolithic solid state green laser as a potential source for vibrometry systems, 9th Int. Confercnceo n Vibration Measarcments laser and Noncontact Techniques, Ancona 2010
EMF electrooptical sensor based on microchip lasers
Spectral analysis in the case of the electric field
measurement E = 80V/m and the frequency
FRF = 5MHz (X: 20MHz/div)
Electric field sensor calibration in TEM line
antenna
electrode
crystal LiNbO3
laser beam
P0
n2n1
LiNbO3
L0
l1 l2
2/22112
U
tU
lnln
ct
Pumping diode= 808 nm
LiNbO3
Nd: YVO4
All dielectric sensorAntenna
SignalProcessing
PIN diode
dResonator
Fabry-Perota
R
R
nd
cC
1
2
AutomaticFrequency
Control
C
Fibercoupler
PIN diode
PINdiode
Pumping diode = 808 nm
Local oscillator
LiNbO3
Nd:YVO4
Nd:YVO4
All dielectric sensor
Polarizationmaintain fiber
Antenna
SignalProcessing
Fiber
coupler
Antończak Arkadiusz, Abramski Krzysztof: Microchip laser antenna, Proceedings of 2005 7th International Conference on Transparent Optical Networks with 4th European Symposium on Photonic Crystals, Barcelona, Spain, July 3-7, 2005. vol. 2 Piscataway, IEEE, pp. 359-362
Laser micromachining
Semiconductors:Si (silicon), Ge (germanium), GaAs (g allium arsenide), InP (indium phosphide),
Ceramics and glass:Al2O3 (alumina), AlN (aluminum nitride), LTCC ceramics, fused silica, BK7, etc.
Metals and alloys:Titanium, tungsten, molybdenum, tantalum, indium, stainless steel, copper, aluminum,
Plastics and Polymers:Poly-methyl methacrylate (PMMA), Teflon (PTFE), polyamide,
Examples of laser micromachining
150μm diameter, silicon
Laser microdrilling
60μm x 60μm square hole in a silicon chip with a thickness of 350μm,
micro-holes in fuel injection systems
diamond cutting 0.4 mm thick sapphire tungsten slit 0.01mm thick 0.1mm
Laser microcutting
Examples of laser micromachining
aluminum block with a group of squares separated 500μm 100μm gap
Laser micromilling
structure 2,5D structure 3D structure 3D diameter 1,4mm
micro-antenna applications
50μm holes in the packaging of biomedical
microvia through PCB microlenses (polymer)
Other:
Laser color marking
ColorPower
[W]Speed [mm/s]
Hatching [mm]
Repetition
Frequency [kHz]
RED (light) 8 50 0,03 100RED (dark) 10 50 0,04 100GREEN (light) 8 50 0,05 90GREEN (dark) 10 100 0,01 100BLUE (light) 10 100 0,05 100BLUE (dark) 12 150 0,05 100GOLD (light) 15 250 0,05 100GOLD (dark) 12 200 0,05 100BROWN 14 25 0,05 100SILVER 10 250 0,05 100PURPLE (light) 9 100 0,02 100PURPLE (dark) 12 100 0,04 100NAVY (blue) 8 25 0.01 100
Red / raspberry color
Blue
Green
Yellow/ gold
Fast prototyping of PCB (Printed Circuit Board) using laser
micromachining
For different substrates:a) FR-2 b) CEM-1; c) FR-4
Resolution tested up to 5 mils (~120μm)
Technology useful for:circuit boards, RFID,micro-strip antennas,etc.
- without preparation of photographic film
Idea of single channel laser – fiber vibrometer
P. R. Kaczmarek, M. Kazimierski,A. Waz and K. M. Abramski Laser-Fiber Vibrometry/Velocimetry Using Telecommunications Devices Proc. SPIE 5503, pp 329-33, 2004
4 – Channel Fiber-Laser Vibrometer
A. T. Waz, P. R. Kaczmarek and K. M. Abramski Laser-fibre vibrometry at 1550 nm, Meas. Science and Technology vol. 20 105301 (8pp), 2009
A. Waz, P. Kaczmarek, M. Nikodem and K. M. Abramski WDM optocommunication technology used for multipoint vibrometry Proc. SPIE 7098, 2008
Vibrometry signal processing
Data acquisition software
4 – Channel Fiber-Laser Vibrometer
Green laser vibrometry based on single frequency microchip laser
FMDemodulator
Mirror
/4
PBS
+2fB
RF Spectrum Analyzer
Brag CellfB = 80MHz
+fB
/4
Moving object
Polarization 45o
Single Frequency Solid State Green Laser
(532nm)
Polariser
Mirror
PBS
+fB
/4 Moving objectPolarization 45o
Brag CellfB = 80MHz
PBS
BS
FMDemodulator
RF Spectrum Analyzer
Single Frequency Solid State Green Laser
(532nm)
Second Photodetector
0
5
10
15
20
25
30
35
40
45
0 2 4 6 8 10 12 14 16 18 20
S/N
ratio
[dB]
Laser output power @532nm [mW]
RBW 200kHz
RBW 510kHz
RBW 1MHz
S/N ratio versus laser output power (L = 0.25m)
0
5
10
15
20
25
30
35
40
0 100 200 300 400 500 600
S/N
ratio
[dB]
Distance to moving object [cm]
RBW 200kHz
RBW 510kHz
RBW 1MHz
S/N ratio versus distance to the moving object (PLASER_= 10.5mW)
Arkadiusz J. Antończak, Paweł Kozioł, Jarosław Z. Sotor, Paweł R. Kaczmarek, Adam T. Wąż, Krzysztof M. Abramski, Elementary experiments in green laser vibrometry, 9th International Conference on Vibration Measurements by Laser and Noncontact Techniques, Advances and Applications, Ancona, 22-25 June 2010 / Ed. Enrico Primo Tomasini. Bellingham, Wash.: SPIE
Laser & Fiber Electronics Group
Thank you for your attention!