Period, amplitude and phase through FFT in MATLAB
Suppose your signal is x. 

L = length(x);                   %%% Length of your signal
nfft = L;                        %%% number of points in your fft
res = fft(x,nfft)/nfft;          %%% taking fft of your signal
f = fs/2*linspace(0,1,nfft/2+1); %%% defining correct frequency axis
res = res(1:nfft/2+1);           % half spectrum becos fft result is mirror
figure, plot(f,abs(res));        % here you can amplitude in freq domain  
figure, plot(f,angle(res));      % here you can see phase in freq domain.


Hopefully, this will be helpful to you.