1. Laser & Fiber Electronics Group
Institute of Telecommunications, Teleinformatics and Acoustics Wrocław University of Technology

2. 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

3. Fiber lasers and amplifiers:
Our research
Fiber lasers and amplifiers:
MOPA systems
Optical frequency combs
Solid state diode pumped single frequency microchip lasers
Laser micromachining
Laser-fiber vibrometry

4. 2-stage All-Fiber MOPA setup
Experimental setup
Output signals (SNR > 50 dB)
~37 dB gain nm
4.8 W output power (ŋ = 24%)
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
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)

5. Self-made additional equipment
Water-cooler
Laser Diode Temperature Controller
Cooling blocks for 3*10W diodes
High Power Laser Diode Temperature Controller

6. 2-stage MOPA – pulsed regime
Pulse-shaping effect
8 ns output pulse
Peak power vs. Repetition rate
Pulse distortion
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.
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

7. 3-stage Fiber-MOPA system
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)
35W diodes
Pump injection system
LMA Fiber
Tapered splice
Cladding mode-stripper

8. 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, (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, (2008).

9. Optical frequency comb stabilization
Long-term frequency fluctuations less than 0,93 MHz
Michał Nikodem, Krzysztof Abramski, „Controlling the frequency of the Frequency Shifted Feedback fiber laser using injection-seeding technique,” Optics Communications 283 (2010), pp
Michał Nikodem, Ewelina Kluzniak, Krzysztof Abramski, „Wavelength tunability and pulse duration control in frequency shifted feedback Er-doped fiber lasers,” Optics Express 17, (2009).

10. Single frequency Nd:YAG/KTP laser
where:
Δn = 0,0844 – is the natural birefringence of KTP (nz - ny), l2 – geometrical length of KTP
Antończak Arkadiusz, Sotor Jarosław, Abramski Krzysztof: Single frequency green laser with birefringent filter. W: Proceedings of th International Conference on Transparent Optical Networks with 5th European Symposium on Photonic Crystals.., Nottingham, UK, June 18-22, Vol. 4 / [Ed. M. Marciniak]. Piscataway, NJ : IEEE, cop pp

11. Single frequency Nd:YAG/KTP laser
single frequency / TEM00 mode operation,
output power (at pumping power: P808 = 1W): > 532nm ~ 1064nm
frequency tune: ∆ν0 ~
110GHz
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

12. Nd:YAG/BIBO – 473nm for underwater vibrometry
output = 1W ~ 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 ,

13. Microchip laser stabilized by fiber Bragg grating
Δλm = 0,35pm/oC => (93MHz/oC)
frequency stability at the level of 10-7,
simple frequency stabilization of the laser for metrological purposes.
Antończak Arkadiusz, Sotor Jarosław, Abramski Krzysztof: Single frequency solid state laser stabilized by FBG. W: Proceedings of th Anniversary International Conference on Transparent Optical Networks with 7th European Symposium on Photonic Crystals, Athens, Greece, June 22-26, 2008.

14. Fast Frequency Control of Microchip Lasers
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, May, 2005, Deutsche Gesallschaft fur Angewandte Optik,

15. Single frequency green (532nm) laser with YVO4 beam displacer - conception
Crystals cutting and single frequency laser configuration with YVO4 beam displacer
Features:
birefringent filter formed by YVO4 beam displacer and KTP crystal,
possibility of monolithic realization,
resistant to environmental hazards.
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,

16. 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)
Practical realization of single frequency DPSS laser
Experimental set-up of single frequency DPSS laser
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).

17. Monolithic single frequency laser – parameters
a) b) c) d)
Features:
single frequency operation temperature range with mode hopping (Fig.a),
output 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
J.Z. Sotor, A.J. Antończak, K.M. Abramski, Single-longitudinal mode miniature, green solid state laser, Europhoton 2010, Hamburg 29.08–
J.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

18. 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
Antończak Arkadiusz, Abramski Krzysztof: Microchip laser antenna, Proceedings of th International Conference on Transparent Optical Networks with 4th European Symposium on Photonic Crystals, Barcelona, Spain, July 3-7, vol. 2 Piscataway, IEEE, pp 18

19. 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,

20. 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

21. 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:

22. Repetition Frequency [kHz]
Laser color marking
Red / raspberry color
Blue
Green
Yellow/ gold
Color
Power [W]
Speed [mm/s]
Hatching [mm]
Repetition Frequency [kHz]
RED (light) 8 50
0,03
100
RED (dark) 10
0,04
GREEN (light)
0,05 90
GREEN (dark)
0,01
BLUE (light)
BLUE (dark) 12
150
GOLD (light) 15
250
GOLD (dark)
200
BROWN 14 25
SILVER
PURPLE (light) 9
0,02
PURPLE (dark)
NAVY (blue)
0.01

23. Resolution tested up to 5 mils (~120μm)
Fast prototyping of PCB (Printed Circuit Board) using laser micromachining
- without preparation of photographic film
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.

24. 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 , 2004

25. 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 (8pp), 2009
A. Waz, P. Kaczmarek, M. Nikodem and K. M. Abramski WDM optocommunication technology used for multipoint vibrometry Proc. SPIE 7098, 2008

26. Vibrometry signal processing

27. Data acquisition software

28. 4 – Channel Fiber-Laser Vibrometer

29. Green laser vibrometry based on single frequency microchip laser
S/N ratio versus laser output power (L = 0.25m)
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, June 2010 / Ed. Enrico Primo Tomasini. Bellingham, Wash.: SPIE

30. Laser & Fiber Electronics Group
Thank you for your attention!