Pulsed lasers used in science and medicine produce very short bursts of electromagnetic energy. If the laser light wavelength is 1062 nm (this corresponds to a Neodymium-YAG laser), and the pulse lasts for 40 picoseconds, and 1.1 x 104 wavelenghs are found in the laser pulse, how short would the pulse need to be to fit in one wavelength?
frequency*wavelength=speedlight
1/period*wavelength=speedlight
period= wevelength/speedlight solve it.
Thank you!
To determine how short the pulse would need to be to fit in one wavelength, we can use the formula:
Pulse duration = Total pulse length / Number of wavelengths
Given:
- Laser light wavelength = 1062 nm
- Pulse duration = 40 picoseconds (40 ps)
- Number of wavelengths = 1.1 x 10^4 wavelengths
First, let's convert the pulse duration from picoseconds to nanoseconds so that the units match:
Pulse duration = 40 ps = 40 x 10^-3 ns = 4 x 10^-11 ns
Now, let's calculate how much time is covered by 1.1 x 10^4 wavelengths:
Total pulse length = 1.1 x 10^4 wavelengths x 1062 nm
Since the pulse length is in nanometers (nm), we need to convert it to nanoseconds (ns) to match the units of the pulse duration. The conversion factor we'll use is the speed of light: 3 x 10^8 m/s.
Total pulse length = (1.1 x 10^4 wavelengths x 1062 nm) / (3 x 10^8 m/s)
Dividing the wavelength by the speed of light would give the total time in seconds, but since we want it in nanoseconds, we'll multiply by 10^9:
Total pulse length = (1.1 x 10^4 x 1062 nm) / (3 x 10^8 m/s) * 10^9 = 3.98 x 10^-11 ns
Finally, we can find the pulse duration needed to fit in one wavelength:
Pulse duration = 3.98 x 10^-11 ns / 1.1 x 10^4 = 3.62 x 10^-15 ns
Therefore, the pulse would need to be approximately 3.62 femtoseconds (fs) to fit within one wavelength.