Question

A common optical instrument in a laser laboratory is a beam expander. One type of beam expander is shown in FIGURE P35.29.

The parallel ray of a laser beam of width ${\omega }_1$enter from the left.

a. For what lens spacing d does a parallel laser beam exit from the right?

b. What is the width ${\omega }_2$of the exiting laser beam?

Short answer

a.)$d-f_2+f_1$

b.)${\omega }_2-\frac{f_2}{{}_{}}$

Step-by-step solution

Step.1 Given information

a.)From the given values shown in FIGURE

$d=f_2-\left|f_1\right|$

If $f_1<0,$this equationto

Step 2. Explanation

b.) we need to find width ${\omega }_2$

From triangles picture, we get Value of ${\omega }_2$

$\frac{{\omega }_1}{\left|f_1\right|}=\frac{{\omega }_2}{f_2}$

$\Rightarrow {\omega }_2=\frac{f_2}{\left|f_1\right|}{\omega }_1$

So, if is$f_2>f_1$and our answer then shows is ${\omega }_2>{\omega }_1$