/trunk/MSc_Matlab_Code/Misc/Toolboxes/OSCAR_V1.3/Calculate_Pcirc/CreateField.m

http://thesisyossim.googlecode.com/ · MATLAB · 100 lines · 52 code · 38 blank · 10 comment · 0 complexity · c29b5101f75426ee5f3d714b1bc8318f MD5 · raw file 

    

  1. clear all

    2. 

  2. 

    3. 

  3. global Grid

    4. 

  4. global Laser

    5. 

  5. global Mirror

    6. 

  6. global ITM

    7. 

  7. global ETM

    8. 

  8. global Length;

    9. 

  9. global Mat_propagation

    10. 

  10. global Field

    11. 

  11. 

    12. 

  12. 

    13. 

  13. %-----------------------------------------------------------------

    14. 

  14. fprintf('\n*******************************************************\n ')

    15. 

  15. fprintf('                   OSCAR FFT code                       \n ')

    16. 

  16. 

    17. 

  17. %--------------------- Parameters simulations --------------------

    18. 

  18. 

    19. 

  19. Grid.Num_point = 128;

    20. 

  20. Grid.Length = 0.30;

    21. 

  21. 

    22. 

  22. % Parameters of the input laser beam

    23. 

  23. Laser.lambda = 1064e-9;

    24. 

  24. Laser.beam_radius = 0.0200;

    25. 

  25. Laser.wavefront_radius = -2000;

    26. 

  26. 

    27. 

  27. Laser.power = 1; 

    28. 

  28. 

    29. 

  29. Laser.amplitude = sqrt(Laser.power*2/(pi*Laser.beam_radius^2)); % Amplitude for TEM00 input beam

    30. 

  30. %--------------------- Cavity parameters ---------------------------

    31. 

  31. 

    32. 

  32. Length_cav = 1000;

    33. 

  33. 

    34. 

  34. ITM.RofC = 2500;

    35. 

  35. ETM.RofC = 2500;

    36. 

  36. 

    37. 

  37. Mirror.Diam = 0.25;

    38. 

  38. 

    39. 

  39. ITM.T =  0.005;

    40. 

  40. ETM.T =  50E-6;

    41. 

  41. 

    42. 

  42. ITM.L = 50E-6;

    43. 

  43. ETM.L = 50E-6;

    44. 

  44. 

    45. 

  45. ITM.R = 1 - ITM.T - ITM.L;

    46. 

  46. ETM.R = 1 - ETM.T - ETM.L;

    47. 

  47. 

    48. 

  48. 

    49. 

  49. ITM.r = sqrt(ITM.R);

    50. 

  50. ETM.r= sqrt(ETM.R);

    51. 

  51. ITM.t = sqrt(ITM.T);

    52. 

  52. ETM.t= sqrt(ETM.T);

    53. 

  53. 

    54. 

  54. Refrac_index = 1.45;

    55. 

  55. 

    56. 

  56. % Variable

    57. 

  57. 

    58. 

  58. Laser.k_prop = 2*pi/Laser.lambda;

    59. 

  59. Grid.step = Grid.Length/Grid.Num_point;

    60. 

  60. 

    61. 

  61. 

    62. 

  62. %--------------------- Create the scale for the grid -----------

    63. 

  63. 

    64. 

  64. Grid.vector = 1:Grid.Num_point;

    65. 

  65. 

    66. 

  66. Grid.axis = -Grid.Length/2 + Grid.step/2 + (Grid.vector-1)*Grid.step;

    67. 

  67. Grid.axis_fft = -1/(2*Grid.step) + (Grid.vector-1)*1/(Grid.Num_point*Grid.step);    

    68. 

  68. 

    69. 

  69. %-------------------- Create mirror mask --------------------------

    70. 

  70. 

    71. 

  71. [Grid.X,Grid.Y] = meshgrid(Grid.axis);

    72. 

  72. [Grid.FFT_X,Grid.FFT_Y] = meshgrid(Grid.axis_fft);

    73. 

  73. 

    74. 

  74. Grid.D2_square = Grid.X.^2 + Grid.Y.^2;

    75. 

  75. Grid.D2 = sqrt(Grid.D2_square);

    76. 

  76. 

    77. 

  77. Mirror.mask_index = find (Grid.D2 < (Mirror.Diam/2));

    78. 

  78. Mirror.mask = zeros(Grid.Num_point,Grid.Num_point,'double');

    79. 

  79. Mirror.mask(Mirror.mask_index) = 1;

    80. 

  80. 

    81. 

  81. %-------------------- Create propagation matrix  --------------------------

    82. 

  82. Mat_propagation = complex(zeros(Grid.Num_point,Grid.Num_point,'double'));

    83. 

  83. 

    84. 

  84. Mat_propagation = exp(i*(-Laser.k_prop*Length_cav + ...

    85. 

  85.             pi*Laser.lambda*(Grid.FFT_X.^2 + Grid.FFT_Y.^2)*Length_cav));

    86. 

  86.         

    87. 

  87. %--------------------Create mirrors matrix -------------------------------

    88. 

  88. 

    89. 

  89. CreateMirror;

    90. 

  90. 

    91. 

  91. %------------------- Create input EM field ----------------------

    92. 

  92. 

    93. 

  93. Field.Start = complex(zeros(Grid.Num_point,Grid.Num_point,'double'));

    94. 

  94. 

    95. 

  95. Field.Start = Laser.amplitude .* exp(-Grid.D2_square/Laser.beam_radius^2).* ...

    96. 

  96.             exp(-i*Laser.k_prop.*Grid.D2_square./(2*Laser.wavefront_radius));
    97.