#In order to force a constant effective index, set the group index and effective index to the same value
#In order to enter optical length simply set effective index/group index to '1'

#Parameters to generate 
#Robi Boeck, Nicolas A. Jaeger, Nicolas Rouger, and Lukas Chrostowski, 
#"Series-coupled silicon racetrack resonators and the Vernier effect: theory and measurement"
#Opt. Express 18, 25151-25157 (2010) 

#The center frequency for the waveguide propagation properties

f0 = getnamed("ONA1","center frequency");
ng = 4.306;
neff = ng;
lambda = c / f0;

#filter parameters
loss = 3 / 1e-2; 	# 3 dB/cm

# not optimized ==================================
k1 = 0.35;		#power coupling coeff 1
k2 = 0.1;		#power coupling coeff 2
k3 = 0.35;		#power coupling coeff 3
l1 = 127.91e-6; 	#ring 1 length
l2 = 99.487e-6;	#ring 2 length
# ===================================================

optics_express_v_18_i_24_pp2151_2010_circuit;
run;
x = getresultdata("ONA1","input 1/mode 1/gain","x");
y1 = getresultdata("ONA1","input 1/mode 1/gain","y");

# optimized =======================================
k1 = 0.015;		#power coupling coeff 1
k2 = 0.00005;	#power coupling coeff 2
k3 = 0.015;		#power coupling coeff 3
l1 = 42.637e-6; 	#ring 1 length
l2 = 28.425e-6;	#ring 2 length
# ===================================================

optics_express_v_18_i_24_pp2151_2010_circuit;
run;
y2 = getresultdata("ONA1","input 1/mode 1/gain","y");

plot( x, y1, y2 );