The general form of a Lindblad equation has the form
$$\frac{d\rho}{dt}=-i[H,\rho]+\sum\gamma(A{\rho}A^{\dagger}-\frac{1}{2}A^{\dagger}A\rho-\frac{1}{2}\rho{A}^{\dagger}A)$$
How can I find Collapse operator for a specific case, For example, for a single Bosonic mode, For a purely gaussian process the Lindbladian is taken to be of the form given in this link. Here for the Amplitude damping effect $A$ is taken as $\sqrt{2}a$ and $L^{\dagger}=\sqrt{2}a^{\dagger}$ and for the Purely Dephasing case $A=A^{\dagger}=\sqrt{2}a^{\dagger}a$. But I don't understand how can I get these Collapse operators for these specific cases.