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CUHK 27th of November 2003 1
FIBRE LASERS, CRYSTAL FIBRES AND WHAT TO DO WITH THEM
Presentation to the Chinese University of Hong Kong, November 27th 2003
Guillaume Vienne, Research Center COM, Technical University of Denmark
1. Fiber lasers- High power (Cladding pumped)- Single-frequency (DFBs)- Short pulse (Mode locked)
2. Holey fibres’overview - Photonic Crystal A/S
3. A few applications of PCFs- Spectro- telecom- sensors
CUHK 27th of November 2003 2
CARS setup
fs-lase r
M O
M O
P C F
d e la y
P M T
M O
M O
s a m p le
fi lte rs
x
yz
B S
D M
CARS Experimental setup
40 mm PCF, 0=790 nm
Standard fs laser: 800 nm,50 fs, 76 MHz, 300 mW
Sample is piezo scanned (xy)
Sample: coverglasswith polystyrene beads
Courtesy of Jakob Juul Larsen, NKT Research
CUHK 27th of November 2003 3
Polystyrene:C-H stretch at 3000 cm-1
P = 640 nm,S = 795 nm,E ~ 3000 cm-1
CARS ”mini”continuum
700 750 800 850 9000.0
0.2
0.4
0.6
0.8
1.0
550 600 650 700 750 800 850 900 950 10000.0
0.2
0.4
0.6
0.8
1.0
Inte
nsity
Wavelength [nm]
PCF (0=790 nm)pumped with 25 mW
Courtesy of Jakob Juul Larsen, NKT Research
CUHK 27th of November 2003 4
0
5
10
15
20
05
1015
20
CA
RS
sig
nal [
a.u.
]
µm
Future work: frequency tuning z-scans
CARS signalFWHM ~100 fs
CARS results
S=620 nm, E=3550 cm-1
CARS signal drops to 1%
Courtesy of Jakob Juul Larsen, NKT Research
CUHK 27th of November 2003 5
Two-photon fluorescence detectionDouble-clad PCF with LMA inner cladding
– High intensity of pump beam (guided in single-mode core)
– High NA core (defined by outer cladding) efficiently collects fluorescence
– Single fiber device
– Efficiency enhanced 40x
Reference:Myaing et al.Opt. Lett. 28, 1224 (2003)
Fiber
SampleDichroic Mirror
Filter
Ti: Sapphire Laser
DispersionPrecompensator
RhodamineJELL-O®
Spe
ctrometer
PMTPhoton Counter
CUHK 27th of November 2003 6
Tajima et al.(NTT) OFC´03
ECOC’03 Tutorial, Anders Bjarklev
TRANSMISSION?
CUHK 27th of November 2003 7
Fiber Characteristics
PCFfor transmission
L = 2.6 and 3 km
D = 32 ps/(nm.km) at 1550 nm
S = 0.067 ps/(nm2.km)
= 1.2 W-1.km-1
Loss = 1.7 dB/km
Highly non-linear PCFfor signal processing
L = 50 m
D = 0 ps/(nm.km) at 1552.5 nm
S = -0.26 ps/(nm2.km)
= 18 W-1.km-1
Loss = 58 dB/km
Same scale
Near field
1530 1560 1590 1620
-25
-20
-15
-10
-5
0
5
10
15
disp
ersi
on [p
s/km
/nm
]
wavelength [nm]
dispersion measurement by Kim P. Hansen - Crystal Fibre A/S, PD-paper FA9, OFC 2002
CUHK 27th of November 2003 8
Transmission with OPC at 40 Gbit/s through PCF
PD
CW MZM OBFCW
PC
HNL-PCF
PCF
PCFEDFA
Rx
OBF
PC
S= 1548.86 nm
C= 1555.24 nm
P= 1552.04 nm
2.6 km
3 km
transmitter output after 2.6 km PCF
231-1 PRBS
C. Peucheret & al, Research Center COM
CUHK 27th of November 2003 9
160 Gb/s – 10Gb/s Demultiplexing
loop filter
-
10 GHz
160 Gb/s OTDM data
PCF (50 m)
PC
NOLM
MOD BERML-FRLMUX
SMF 80 km
DCF 12 km
EAM
x4
PD
ERGO PGL
clock recovery
transmitter
PDVCO
High NL coeff -> Short Length -> more stability, less disp & walk offL.K. Oxenløwet & al, Research Center COM
CUHK 27th of November 2003 10
Bend sensor (multi-core PCF)
Reference:Blanchard et al.Smart Mater. Struct. 9, 132 (2000)
Velocimetry:MacPherson et al.,Opt. Comm. 223, 375-380 (2003)
Multi-core PCF bend sensor– PCF with 3 uncoupled cores
– Detect optical phase difference
– Two-dimensional bend sensor
Advantages– Single fiber device
– Relative core positions fixed
– Less sensitive to temperature gradients
– Large freedom in design of fiber (number
and positions of cores)
CUHK 27th of November 2003 11
Evanescent-wave sensing
PCF based evanescent-wave sensors– Evanescent field penetrates into air-holes
– Long interaction length between sample and light
– Measurements on gases and liquids
References:T. Monro et al., Electron. Lett. 35, 1188 (1999)
Y.L Hoo et al., Opt. Eng. 41, 8 (2002)
Y. Hoo et al.IEEE Phot Tech. Lett.15, 1434 (2003)
Absorption measurement on acetylene gas in air-holes of 75cm PCF
CUHK 27th of November 2003 12
Selectivity by hybridization
References:Hoiby et al. Eurosensors 2003
Kiiveri et al., 1996
Hybridization
Single strand Oligo-DNA immobilized inside the air holes
Streptavidin
Biotin
Oligo
Cy5
Cy5
Streptavidin
Biotin
Oligo
Cy5
Cy5
CUHK 27th of November 2003 13
Evanescent-wave sensing in hollow-core PCF
Reference:Jensen et al. CLEO2003
Hollow-core PCF:– Sample volume < 30nL/cm– Sample in all air holes is probed by light
0.70 0.75 0.80 0.85 0.90 0.950
5
10
15
Pen
etr
atio
n (
%)
d/
TT1: = 4m, = 0.65m:
Fundamental mode
– Strong penetration of optical field into sample550 600 650 700
0.0
0.4
0.8
H2O
Cy5-DNA (aq.)
Abs
orba
nce
Wavelength (nm)
CUHK 27th of November 2003 14
Spectrometer
658nm
Expose fiber from the side with laser
Fluorescence measurements Air-Clad PCF with Cy5-Oligo-DNA hybridized on the
inside of the air holes
600 650 700 750 8000
100
200
300
400
Flu
ore
sce
nce
(co
un
ts)
Wavelength (nm)
Cy5-dummy-DNA Cy5-Oligo-DNA
J. B. Jenssen & al, Research Center COM
CUHK 27th of November 2003 15
77°C
89°C
91°C
94°C
Fill & Play: Liquid crystals in PCF
Microheater
T. Tanggaard & al, Research Center COM