Question

The world's most powerful laser is the LFEX laser in Japan. It can produce a 2 petawatt(2×10^15W) laser pulse that last for 1 ps. The laser is focused onto a small spot that is 30 μm in diameter. What is the light intensity within this spot?

Answer 1

The light intensity within the spot can be calculated using the formula I = P/A, where I is the light intensity, P is the power of the laser pulse, and A is the area of the spot. Given that the power of the laser pulse is 2 petawatts and the diameter of the spot is 30 μm, we can calculate the light intensity within the spot.

Step-by-step explanation:

The light intensity within the spot can be calculated using the formula:

I = P/A

where I is the light intensity, P is the power of the laser pulse, and A is the area of the spot.

The power of the laser pulse is 2 petawatts (2x10^15 W), and the area of the spot can be calculated using the formula for the area of a circle:

A = πr^2

where r is the radius of the spot (which is half the diameter). Given that the diameter is 30 μm, we can calculate the radius as 15 μm.

Substituting the values into the formulas, we get:

P = 2x10^15 W, A = π(15x10^-6 m)^2

Finally, we can calculate the light intensity:

I = P/A

Answer 2

`2.82942* 10^(24)\ W\m^2`

Step-by-step explanation:

d = Diameter of spot = 30 μm

r = Radius of spot =
`(d)/(2)=(30)/(2)=15\ mu m`

P = Power of the laser =
`2* 10^(15)\ W`

A = Area =
`\pi r^2`

Intensity is given by

`I=(P)/(A)\\\Rightarrow I=(2* 10^(15))/(\pi* (15* 10^(-6))^2)\\\Rightarrow I=2.82942* 10^(24)\ W/m^2`

The light intensity within this spot is
`2.82942* 10^(24)\ W/m^2`