Cartoon of monochromator movements
Matlab code 

% Program to animate crystal movements in a four-bounce mono

clear; close all;

 

figure('units','pixels','position',[0 0 1920 1080],'ToolBar','none');

vid = VideoWriter('fourbounceMovement.mp4','MPEG-4');

vid.FrameRate = 30;    % Default 30

vid.Quality = 100;    % Default 75

open(vid);

set(0,'defaultfigurecolor',[1 1 1]);

set(gca,'linewidth',7);

 

% Some dimensions of the mono

h= 0.1; % beam half height

d = 1; % channel height

thSt = 35; % starting angle

thEnd = 15; % ending angle

thStep = -0.25; % angle step size

mirrorX = 4.25; % mirror plane of two crystals in the four-bounce configuration

 

fwd = [thSt:thStep:thEnd];

 

X1x = [-1.5 1.0 1.0 -1.5]; % x-coords X1 first channel cut

X1y = [0 0 -0.5 -0.5]; % y-coords X1 first channel cut

X2x = [-1 4.5 4.5 -1]; % x-coords X2 first channel cut

X2y = [1 1 1.5 1.5]; % y-coords X2 first channel cut

Brix = [-1 1 1 -1]; % x-coords bridge piece first channel cut

Briy = [0 0 1 1]; % y-coords bridge piece first channel cut

mirX1x = 2*mirrorX - [-1.5 1.0 1.0 -1.5]; % x-coords X1 second channel cut

mirX2x = 2*mirrorX - [-1 4.5 4.5 -1]; % x-coords X2 second channel cut

mirBrix = 2*mirrorX - [-1 1 1 -1]; % x-coords bridge piece second channel cut

 

% Create rgb progression through a rainbow

bot = 0:8:120; % 0 to 7f in 16 steps

top = 128:8:248; % 80 to ff

all = 0:16:240; % 0 to ff

botc = 0*all; % vector of zeros

midc = botc + 127; % vector of 127s

topc = botc + 255; % vector of 255s

rcomp = [top topc topc flip(all) botc botc bot flip(bot)]/256; % R in rgb

gcomp = [botc bot top flip(top) midc flip(bot) botc botc]/256; % G in rgb

bcomp = [botc botc botc botc bot midc midc flip(bot)]/256; % B in rgb

 

grey = [0.5 0.5 0.5];

dkgrey = [0.3 0.3 0.3];

 

% for th = [fwd flip(fwd)]

 

for th = [fwd flip(fwd)]

    newplot

    hold on

    OA = d/sind(th);

    BLx = -h/tand(th);

    BLy = -h;

    BRx = h/tand(th);

    BRy = h;

    TLx = BLx + OA*cosd(2*th);

    TLy = BLy + OA*sind(2*th);

    TRx = BRx + OA*cosd(2*th);

    TRy = BRy + OA*sind(2*th);

    X2 = fill(X2x,X2y,grey,'LineStyle','none');

    rotate(X2,[0 0 1],th,[0,0,0]);

    Bridge = fill(Brix,Briy,dkgrey,'LineStyle','none');

    rotate(Bridge,[0 0 1],th,[0,0,0]);

 

    for ii = -h:h/10:h

        axis off

        axis equal

        x = [-4,ii/tand(th)];

        y = [ii,ii];

        colIndex = round(6*(1 + (ii+h)*90));

        plot(x,y,'color',[rcomp(colIndex),gcomp(colIndex),bcomp(colIndex)],'LineWidth',2);

    end

    beamColInd = round(abs((thSt - th)/(thSt - thEnd))*120) + 1;

    monoBeam1 = fill([BLx BRx TRx TLx],[BLy BRy TRy TLy],...

        [rcomp(beamColInd),gcomp(beamColInd),bcomp(beamColInd)],'LineStyle','none');

    set(monoBeam1,'facealpha',.5)

 

 

    X1 = fill(X1x,X1y,grey,'LineStyle','none');

    rotate(X1,[0 0 1],th,[0,0,0]);

 

    % Second channel-cut crystal

    BLx = 2*mirrorX - BLx;

    BLy = -h;

    BRx = 2*mirrorX - BRx;

    BRy = h;

    TLx = 2*mirrorX - TLx;

    TLy = BLy + OA*sind(2*th);

    TRx = 2*mirrorX - TRx;

    TRy = BRy + OA*sind(2*th);

    mirX2 = fill(mirX2x,X2y,grey,'LineStyle','none');

    rotate(mirX2,[0 0 1],-th,[2*mirrorX,0,0]);

    Bridge = fill(mirBrix,Briy,dkgrey,'LineStyle','none');

    rotate(Bridge,[0 0 1],-th,[2*mirrorX,0,0]);

    mirX1 = fill(mirX1x,X1y,grey,'LineStyle','none');

    rotate(mirX1,[0 0 1],-th,[2*mirrorX,0,0]);

    monoBeam2 = fill([TLx TRx 2*mirrorX-TRx 2*mirrorX-TLx TLx],...

        [TLy TRy TRy TLy TLy],[rcomp(beamColInd), gcomp(beamColInd),...

        bcomp(beamColInd)],'LineStyle','none');

    set(monoBeam2,'facealpha',.5)

    monoBeam3 = fill([BLx BRx TRx TLx],[BLy BRy TRy TLy],[rcomp(beamColInd),...

        gcomp(beamColInd),bcomp(beamColInd)],'LineStyle','none');

    set(monoBeam3,'facealpha',.5)

    monoBeam4 = fill([BLx BRx 11.85 12 11.85 BLx],[BLy BRy BRy BRy-h BLy BLy],...

        [rcomp(beamColInd), gcomp(beamColInd),bcomp(beamColInd)],'LineStyle','none');

    set(monoBeam4,'facealpha',.5)

    viscircles([0 0],0.044,'LineWidth',4,'Color','k');

    viscircles([2*mirrorX 0],0.044,'LineWidth',4,'Color','k');

 

    xlim([-4 12]);

    ylim([-1.5 4]);

 

    hold off

    % Store the frame

    frame = getframe(gcf);

    writeVideo(vid,frame);

end

% Output the movie as an mpg file

close(vid);