We discuss the influence of atomic memory effects on the field fluctuations of a laser in a general context. We derive a Fokker-Planck equation for the field that takes into account the long lifetime of the lasing atoms. Using this equation, we discuss two consequences of atomic memory. First, we find that even in the pres. -. nce of saturation, memory effects can lead to a reduction of spontaneousemission noise for short measurement times. Second, we quite generally show that atomic memory effects lead to time-dependent diffusion coefficients.The parameters A. , B , C. , and D are given by either Eq. (22) or (24), depending on whether the injection time t is b. efore or after t =0. We can now substitute Eq. (25) together with Eq. (21) into Eq. (20) and obtain a master equation for the reduced density matrix of the field. The commutators, which appear in Eq. (20), have been evaluated in Appendix A. The final result for the reduced density operator of the field is then found to beX[aa aa p -4a aa p a+6aa p aa -4a pfaa a+p aa aa ]+zopf . ' aN"The drift coefficients in Eq. (28) are found to be d = -6' igg f-(t, t, )B, +g f dt'g f(t, t, )8(t't, )(A, D, }6'-J J +ig' f dt' f dt "g f(t, t, )8(t't, )8(t"t, )[B, (1+2~@') -2C, t".'] J g f 'd-t' j'dt" f ' dt" yf(t, t, )8(t t, )8(t"t, )8(t'"t, )(4~@~' -6+78), J together with its complex conjugate. The diffusion coefficients are given by d@= -6 r'gg f-(t, t )8 +g f dt'g f(t, t )6(t' t )(A -D)6-rgb f(t, t, )B, +g f dt'gf(t, t, )8(t't, )( A, D, )8-J J ig g f-(t, t, )( igt, @+i -', g't, '~8~'-6')+g'f dt'g f(r, t, )8(t' t, )6-J J r &0 J +g'f dr' g f(t, t, )B(r' t, )( -2 'gt, '~8-'8) J r &0 J =g'g f(t, t, )r, C+g'f dt'g f(t, t, )B(t' t, )8-The two terms of order g can be combined into one expression by noting that g g f(t, t, )t 6'+g f dt'g f(t, t, )8(t' t, )C=gg f(t, t, ) f dt'8(t't, )+ f dt'B(t' t, )-1 J (87)Here we have neglected terms of order 1 compared to terms proportional to the intensity~8~of the radiation field.The second and third term in Eq. (86) are the only ones which make contribution in the second order in g. We find r &0 J r. &0 J +g'f dt' g f(t, t, )B(t' t, )Nr &0 J =g f ' dt'g f(t, t, )6(t' t, )A' .We next transform the sum over all atoms into an integration over the injection times t, , i.e. , g~R f dt, , in which R is the mean atomic rate. Substituting the definition (17) for the interaction function f(t, t, ), we obtain our final expression for the terms of order g,