Short Period PPLN and its Potential...
Transcript of Short Period PPLN and its Potential...
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 !