short period ppln and its potential...
TRANSCRIPT
Short Period PPLN and its
Potential Applications
P. Baldi, M. De Micheli, E. Quillier LPMC, Nice
L. Guilbert, J.-P. Salvestrini LMOPS, Metz
S. Tascu Iasi, Romania
V. Shur Ekaterinburg, Russia
Outline Interest of PPLN: example of Optical Parametric
Interactions (OPI) Phase Matching and Quasi-Phase Matching (QPM) Materials for co-propagating OPI PPLN and Integrated Optics
Short Period PPLN Counterpropagating OPI Phase-Matching Other Applications (Bragg gratings…)
Towards Short Period on PPLN Conclusion
PPLN (Periodically Poled Lithium
Niobate)
Co-propagating OPI: Phase Matching
Generalities ωp = ωs + ωi
kp = ks + ki
Pump, ωp
Idler, ωi χ(2)
Signal, ωs
Co-propagating OPI: Phase Matching
Colinear case ωp = ωs + ωi
np ωp = ns ωs + ni ωi
Pump, ωp
Idler, ωi χ(2)
Signal, ωs
Co-propagating OPI: Phase Matching
Colinear case ωp = ωs + ωi
np ωp = ns ωs + ni ωi
Problem with dispersion!
Pump, ωp
Idler, ωi χ(2)
Signal, ωs
Co-propagating OPI: Phase Matching
Colinear case ωp = ωs + ωi
np ωp = ns ωs + ni ωi
Use of birefringence. It works, but Limited choice of materials Restricted range of available wavelengths Non-optimum nonlinear coefficient Possibly high operating temperature, walk-off…
Pump, ωp
Idler, ωi χ(2)
Signal, ωs
Co-propagating OPI: Phase Matching
Colinear case ωp = ωs + ωi
np ωp = ns ωs + ni ωi
Use of birefringence. It works, but Limited choice of materials Restricted range of available wavelengths Non-optimum nonlinear coefficient Possibly high operating temperature, walk-off…
Quasi-Phase Matching
Pump, ωp
Idler, ωi χ(2)
Signal, ωs
Λ
Co-propagating OPI: Quasi-Phase Matching
Colinear case ωp = ωs + ωi
kp = ks + ki+2mπ/Λ
Pump, ωp
Idler, ωi
Signal, ωs
χ(2)
Λ
Co-propagating OPI: Quasi-Phase Matching
Colinear case ωp = ωs + ωi
kp = ks + ki+2mπ/Λ
Advantages of QPM: Free choice of wavelengths Optimized efficiency Phase Matching engineering
Pump, ωp
Idler, ωi
Signal, ωs
χ(2)
Materials for QPM co-propagating OPI
Polymers (like DR1/PMMA)
χ(2)
Materials for QPM co-propagating OPI
Polymers (like DR1/PMMA) Semiconductors (GaAs, GaN)
χ(2)
(images from CRHEA)
Materials for QPM co-propagating OPI
Polymers (like DR1/PMMA) Semiconductors (GaAs, GaN) Dielectrics (KTP, Lithium Tantalate…
χ(2)
(LT-From Oxyde) (KTP-From BrightCrystals)
Materials for QPM co-propagating OPI
Polymers (like DR1/PMMA) Semiconductors (GaAs, GaN) Dielectrics (KTP, Lithium Tantalate… … and Lithium Niobate)
χ(2)
Periodically Poled Lithium Niobate
Transparency range from 0.4 to 4 µm Large nonlinear coefficient (d33= 33pm/V)
QPM by ferroelectric domain poling Λ ~ 6 µm over 3’’ φ, 500 µm thick Down to 3 µm on smaller and thinner sample
Good quality waveguides on PPLN over L= 8cm
Λ=12.1µm Λ=12µm
Integrated Optics on PPLN ωp = ωs + ωi
βp = βs + βi + 2π/Λ
Pump, ωp
Idler, ωi χ(2) Λ
Signal, ωs
From LPMC, Nice
Soft Proton Exchange: - ≤ 0.5 dB/cm losses - PDC efficiency of 10-6 compared to 10-9 for bulk
Short Period PPLN
Counter-propagating OPI Configuration
Pump, ωp
Idler, ωi χ(2) Signal, ωs
Counter-propagating OPI
Configuration
Particular interests relative to co-propagating OPI Natural spatial separation of signal et idler beams Narrow spectral PDC bandwidth Mirrorless OPO Single-channel amplification and conversion All-optical signal processing
Pump, ωp
Idler, ωi χ(2) Signal, ωs
Counterpropagating quasi-phase matching Phase matching
kp = - ks + ki with ks ~ ki : almost impossible !
Counterpropagating quasi-phase matching Phase matching
kp = - ks + ki with ks ~ ki : almost impossible !
Quasi-phase matching kp = - ks + ki + 2mπ/Λ : possible with Λ ~ mλp / np
Counterpropagating quasi-phase matching Phase matching
kp = - ks + ki with ks ~ ki : almost impossible !
Quasi-phase matching kp = - ks + ki + 2mπ/Λ : possible with Λ ~ mλp / np
But Λ ~ 300 to 350 nm ! (over L ≥ 1 cm)
=> Technological bottleneck (high resolution AND large field)
COPI: «old» idea, few realizations Theoretical proposition
Harris, Appl. Phys. Lett. 1966 Phase matching
DFG: Chemla et al., Opt. Com. 1974 PDC: Chemla and Batifol, Appl. Phys. Lett. 1976 in Sodium Nitrite (high birefringence ~ 20%) far from degeneracy (455nm, 495nm and 5.63µm) low efficiency (10-12 for PDC)
COPI: «old» idea, few realizations Theoretical proposition
Harris, Appl. Phys. Lett. 1966 Phase matching
DFG: Chemla et al., Opt. Com. 1974 PDC: Chemla and Batifol, Appl. Phys. Lett. 1976
Quasi-phase matching OPO: Canalias et al., Nature Photonics 2007 first order PPKTP with Λ = 800 nm far from degeneracy (821nm, 1.14µm and 2.94µm) threshold: 1.6 GW cm-2
Bragg Gratings on SpPPLN
x y
On PPLN z – cut
x
z
On PPLN y – cut
Required periods in band C : order m 1 : 0,36 à 0,37 µm 3 : 1,08 à 1,11 µm 5 : 1,81 à 1,86 µm 7 : 2,51 à 2,58 µm
LMOPS, Metz
PPLN: advances on and directions to short periods State-of-the-art of short periods PPLN
Backswitching Direct e-beam Local e-field using AFM Calligraphy… All unsufficient (quality, depth, area…)
PPLN: advances on and directions to short periods State-of-the-art of short periods PPLN
PPLN: advances on and directions to short periods State-of-the-art of short periods PPLN
LPMC: 2 µm period
PPLN: advances on and directions to short periods State-of-the-art of short periods PPLN
Vladimir Shur, Ekaterinburg
PPLN: advances on and directions to short periods State-of-the-art of short periods PPLN
Towards SpPPLN at LPMC Λ = 2 µm (7th order QPM) : classical photolithography Λ = 900 nm (3rd order QPM) : direct optical writting Λ = 300 nm (1st order QPM) : direct electronic writting
Conclusion on Short Period PPLN
High scientific interest
Many applications
New experimental field of interest
Importance of the material aspects
Technological bottleneck
Conclusion on Short Period PPLN
… and many thanks to the CMDO+ for the
support and for the invitation !