//Caption:Program to determine the difference in wavelength of two optical signal
 
//Example 8.4
 
//Page 402
 
c=3*10^8//speed of light 
 
wl=1500*10^-9//wavlength =1500nm  
 
f=[(3*10^8)/wl]  
 
disp('Thus the upper and lower frequencies are determined as 200,001 and 199,999 GHz respectively. The corresponding wavelengths are')
 
lam1=[c/(199999*10^9)]
 
lam2=[c/(200001*10^9)]

//Result

//The difference in wavelenghts is 0.015nm