Hi SungJo, the analytic Morlet wavelet used in the cwt() function and cwtfilterbank as 'amor' is defined in the frequency domain as
where the \hat{U}(\omega) is the unit step in frequency. This makes the wavelet purely analytic. If we ignore the unit step part for a moment, the inverse Fourier transform of 
is
is 
So you can take this as the basic definition of the analytic Morlet wavelet you obtain with 'amor'. Keep in mind a Morlet wavelet is nothing but a modulated Gaussian.
Of course to be technically accurate, we actually have a convolution of the time domain wavelet given above with the inverse Fourier transform of the unit step, so something like
where the \ast denotes convolution.
The above assumed the definition of the Fourier transform and its inverse as
with slight (trivial) differences if a different normalization is used.
Hope that helps,
Wayne
