circ_ap - filters the field through circular aperture.

Calling Sequence

[field_out]=circ_ap(field_in,R[,x_shift[,y_shift]])

Parameters

• field_in :input field.it must be diffractive wavefront.
• R : the radius of the aperture in meters.
• x_shift : the shifts of the X direction in meters. ( default is 0.)
• y_shift : the shifts of the Y direction in meters. ( default is 0.)
• field_out : the output field or diffractive wavefront.

Description

filters the field through a circular aperture of radius R given as the first argument. Two optional arguments define the decentering of the aperture in X and Y directions

Examples

	m=1;
	nm=1e-9*m;
	mm=1e-3*m;
	cm=1e-2*m;

	lambda=550*nm;
	sizes=5*mm;
	
	F1=begin(sizes,lambda);

	F2=circ_ap(F1,sizes/2);
	dwf_fits(F2,"F2");	
	
	F3=circ_ap(F1,sizes/4,sizes/4);
	dwf_fits(F3,"F3");	
 

Author

Chen jingyuan, Gan guangyong (IAPCM, Beijing,China.)

See Also

circle ,   gauss ,   hex_ap ,   rect_ap ,   annul_ap ,   aperture ,