Question

Some neodymium–glass lasers can provide$\mathbf{100}\mathbf{}\mathbf{TW}$of power in$\mathbf{1}\mathbf{.}\mathbf{0}\mathbf{}\mathbf{ns}$pulses at a wavelength of$\mathbf{0}\mathbf{.}\mathbf{26}\mathbf{}\mathit{\mu }\mathbf{m}$. How much energy is contained in a single pulse?

Short answer

Energy contained in a single pulse is $1.0\times {10}^5\text{J}$.

Step-by-step solution

Determine the given quantities

Laser power is:

$\begin{array}{rcl}P& =& 100TW\\ & =& 100\times {10}^{12}\text{W}\end{array}$

Pulse time is:

$\begin{array}{rcl}t& =& 1.0ns\\ & =& 1.0\times {10}^{-9}\text{s}\end{array}$

Determine the concepts of energy and power

The energy depends on power and time.

$E=Pt$

Determine the energy contained in a single pulse

The energy and power are related as

$E=Pt$

Substitute the values and solve as:

$\begin{array}{rcl}E& =& 100\times {10}^{12}\times 1.0\times {10}^{-9}\\ & =& 1.0\times {10}^5\mathrm{J}\\ & & \end{array}$

Energy contained in a single pulse is $1.0\times {10}^5\text{J}$.