I am reading about the coherent states of light (Glauber States), where the starting point is the solution of the stationary Schrödinger equation is solved using analytical and algebraic methods for the 1D-harmonic oscillator. The light is considered as a harmonic oscillator of Hamiltonian $$H = \hbar \omega \left( a^{\dagger}a + \frac{1}{2} \right) \, ,$$ where the operators $a^{\dagger}$ and $a$ are expressed in terms of $p$ and $x$ (momentum and position operators) as $$a=\frac{1}{2m\omega}(x+ip) $$ $$a^{\dagger}=\frac{1}{2m\omega}(x+ip)$$
For a particle of mass, $m$ is ok for me. But for light, the expression of the operators $a^{\dagger}$ and $a$ still working even if light has no mass?