1. M. Beaulieu, L. Abe, P. Martinez, P. Baudoz C. Gouvret
High-contrast imaging at small separation impact of optical configuration on wavefront shaping performances
M. Beaulieu, L. Abe, P. Martinez, P. Baudoz
C. Gouvret

2. Methodology : Guyon et al, AAS, 2013
Context
SPEED project
Detection & characterization of exoplanet in M-dwarf HZ
Methodology : Guyon et al, AAS, 2013
 ELTs, 1 λ/D (Vortex / PIAACMC), Wavefront shaping

3. Wavefront shaping & Fresnel propagation
Talbot effect
Phase only
Amplitude only
zT/8
zT/4 zT
 Use 2 DMs
Several frequencies/optics  end-to-end simulation

4. Goal Study Fresnel propagation effect on performances
Determine limitations when changing the optical configuration
Define optimum DMs locations
Develop end-to-end simulation tool
High-contrast imaging (general) simulation (SPEED)
Define SPEED setup

5. Implementation  Adjust Criteria Baseline setup
~ 25 optics
Perfect coronagraph : removes all light w/o aberrations
2 DMs ~1000 actuators
Adjust
Distances, optical architecture
Random phase (PSD f-α, rms)
Number of random phase realizations (128)
Numerical implementation
Dark hole computation : energy minimization (linear transformation, small phases, perfect coronagraph) 
Code : PROPER / IDL / C++ (data center, 3024 cores shared with users)
Criteria
5σ contrast ratio inside the dark hole

6. Phase number realization
Numerical results
128 phase realizations,
Phase number realization

7. Goal Study Fresnel propagation effect on performances
Determine limitations when changing the optical configuration
Define optimum DMs locations
Develop end-to-end simulation tool
High-contrast imaging (general) simulation (SPEED)
Define SPEED DMs locations
End-to-end simulation
Analytical approach

8. End-to-end simulation : results 1/2
DM1 at pupil plane
Optimum ~ 2 m 7

9. End-to-end simulation : results 2/2
Beaulieu et al, MNRAS, 2017

10. End-to-end simulation : results 2/2
Beaulieu et al, MNRAS, 2017

11. SPEED setup
Beaulieu et al, MNRAS, 2017

12. Analytical approach 1/2 Impact of 1 out-of-pupil plane DM
Approximation : simple setup z
pupil DM Ef
Modulation depends on
DM location z
Focal plane coordinates x and y (dark hole coordinates)

13. Analytical approach 2/2
Efficiency

14. Discussion 1/2
Analytical optimum distance: 0.8 à 4 λ/D

15. Discussion 2/2
Analytical optimum distance: 4 à 10 λ/D

16. Laboratory test
Simple testbed to validate simulation results, acquire know-how on wavefront shaping implementation
Coronagraph easy to implement
Binary coronagraphic mask (checkerboard)
4 coronagraphic zones between 6 and 16 λ/D
2 DMs
Simple testbed : few optics

17. Conclusion End-to-end simulation tool developed @ Lagrange
Collaboration LESIA
Study Fresnel propagation effect
Define optimum DM distance
Application to SPEED
Require large small separation
Can be analytically estimated
On-going lab test to validate results
Take into account pupil discontinuities (gaps, spiders…)
Predict SPEED performances (implement PIAACMC, measured aberration)