Analog Hawking radiation emitted by a perfectly reflecting mirror

Analog Hawking radiation emitted by a perfectly reflecting mirror in ($1+3$)-dimensional flat spacetime is investigated. This is accomplished by studying the reflected frequency and momentum based on Einstein's mirror, instead of the canonical way of solving, if possible, wave equations subjected to a dynamical Dirichlet boundary condition. In the case of a finite-size mirror, diffraction pattern appears in the radiation spectrum. Based on the relevant parameters in the proposed analog black hole evaporation via lasers experiment, in which the Hawking temperature ${T}_{H}\ensuremath{\simeq}0.03\text{ }\text{ }\mathrm{eV}$ and the mirror area $\mathcal{A}\ensuremath{\simeq}(50\text{ }\text{ }\mathrm{\ensuremath{\mu}}\mathrm{m}{)}^{2}$, the Hawking photon yield is estimated to be $N\ensuremath{\simeq}16/\mathrm{laser}$ shot.