Inverse Laplace transform of two-sided and one-sided Laplace transform As I read in Wikipedia, there are two types of Laplace transforms


One-sided Laplace transform: $F(s) = \int_{0}^\infty e^{-st} f(t) dt$
Two-sided Laplace transform: $F(s) = \int_{-\infty}^\infty e^{-st} f(t) dt$


But they give only one formula for Inverse Laplace transform:

$\hspace{3.0cm} f(t) = \frac{1}{2\pi i} \lim_{T \to \infty} \int_{\gamma - i T}^{\gamma + i T} e^{st} F(s) ds$

My question is that, does the type of Laplace transform I use affects the Inverse formula ?

p.s:

I've proved the Inverse Laplace transform above corresponding to Two-sided Laplace transform using Fourier transform. But I've not come up with any idea of proving the correctness of the Inverse Laplace transform corresponding to One-sided Laplace transform.

According to my proof, the Inverse transform above is correct for One-sided transform if $f$ satisfies $f(t) = 0$ $\forall t &lt; 0$. In other words,

$\hspace{3.0cm} f(t) = \frac{1}{2\pi i} \lim_{T \to \infty} \int_{\gamma - i T}^{\gamma + i T} e^{st} F(s) ds$, $\forall t \geq 0$
The inversion formula is the same for both types of transforms:

$$f(t)=\frac{1}{2\pi j}\int_{\alpha-j\infty}^{\alpha+j\infty}F(s)e^{st}ds\tag{1}$$

The difference is in the choice of the constant $\alpha$. The line $\textrm{Re}\{s\}=\alpha$ must be inside the region of convergence (ROC). For causal functions (i.e., functions for which $f(t)=0$ for $t&lt;0$), the ROC is to the right of the pole with the most positive real part, whereas for non-causal functions, the ROC is a vertical strip between two poles.