The pressure generated in an object by thermoelastic expansion due to a very short laser pulse is described:

- M
- = Bulk Modulus [Pa/strain], strain is dimensionless
- = ρc
_{s}^{2}, - c
_{s} - = sound velocity [m/s]
- β
- = Thermal expansivity [strain/degreeC], strain is dimensionless
- ρ
- = Density [kg/m
^{3}] - C
_{p} - = Specific heat [(J/(kg degC)]
- Γ
- = Grueneisen coefficient [dimensionless]
- μ
_{a} - = Absorption coefficient [m
^{-1}] - H
- = Radiant exposure [J/m
^{2}] - W
- = Energy depostion [J/m
^{3}]

The energy deposition W = μ_{a}H [J/m^{3}].

The temperature rise ΔT = (energy deposition)/(rho C_{p}) [degree C].

The strain ε = βΔT [dimensionless].

The stress or pressure = Mε [J/m^{3}] = [kg/(m s^{2}] = [Pa].

The Grueneisen coefficient Γ = Mβ/(ρ C_{p}) [dimensionless].

The units of pressure (P) are (force)/(area). The units of energy deposition (W) are (energy)/(volume) = (force x distance)/(area x distance) in which the distance term cancels to equal (force)/(area). Hence the units of pressure and energy deposition are identical. The conversion factor for pressure is 1 J/m^{3} = 1 Pa = 10^{-5} [bar].