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Journal de bord


Week 1 (October 21-25)

Team leader: Yanis Lesné

Two sub-teams -> Matlab and Zemax

Day 1 : Monday : 

Bibliography: study of different phase masks

-> Yanis, Yilin, Raul, Shutian, Xiaolin
Search for references for the infrared sensor
-> Romain, Gabriel

Brainstorming: overall vision of project progress
-> Romain, Gabriel, Yanis, Yilin, Raul, Shutian, Xiaolin


Day 2 : Tuesday
Optical design on Zemax :
-> Romain, Yanis, Gabriel
We have started to design the optical system, starting with 1 lens in Germanium working with one wavelength. Correction of the spherical aberrations of the 3rd order on the axis. For an object field at 2°, the system is limited by diffraction for N = 1.5.
Then to correct the off-axis aberrations, we add another lens and we have started to increase the field in the image plane and the aperture. 

Filter on Matlab :
-> Raul, Yilin, Gabriel
We have simulated the imaging of an ideal object on the sensor plane, affected by light diffraction and noise during propagation, and used Wiener deconvolution to eliminate these imaging defects. Furthermore, we simulated the optimal form of the Wiener filter under defocus conditions to further optimize the phase mask.

Phase mask on Matlab :
-> Shutian, Xiaolin
We have simulated four different phase masks and integrated the deconvolution process for parameter optimization, aiming to determine the optimal phase conditions.
We choose to work with an exponential phase mask.


Day 3: Wednesday
Everybody : We choose the scene and the noise we will use. It will be a photon noise modelised by a Gaussian law and for the scene, we will use 2 scenes : a black and white street image and an image with high and low frequencies.

Filter and mask matlab:
-> Shutian, Xiaolin, Raul, Yilin
We added the standard of optimization MSE and optimized the parameters of the phase mask. We successfully deconvolute the noisy image to a clear one. 

Optical design on Zemax :
-> Romain, Yanis, Gabriel
We started again from an optical system with only 1 lens to increase step by step the field and the aperture by adding more lenses. We achieved the optimization of the optical system to the maximum FOV = 6 mm. We added the protection of the sensor.


Day 4: Thursday
Everybody : We work on the presentation and the Powerpoint.

Optical design on Zemax :
-> Romain, Yanis, Gabriel
We increased the aperture to N = 1.37 (aperture value = 11) thanks to the aspherisation of the 2 surfaces of the first lens and with conditions on the distance between the 2 lenses and between the second lens and the protection of the sensor.
For the second week : look at materials in order to correct chromatic aberrations (Zinc sulfide or Zinc selenide ?).

Phase mask matlab:
-> Shutian, Xiaolin, Raul, Yilin
We corrected some errors and worked on the exponential phase mask optimization (There are still some issues in the optimization). We created a graph with the influence of different parameters of the phase mask to demonstrate that our results are valid.


Day 5 : Friday
Presentation training + feedbacks