A carbon dioxide laser is an infrared laser. A CO2 laser with a cavity length of 53.00 cm oscillates in the m=100,000 mode. What are the wavelength and frequency of the laser beam?

Video transcript

Welcome back, everyone. We are making observations about properties of erbium doped fiber lasers. Now, we are told that a lab has set up an E D F L with a cavity length of 48 centimeters or 480.48 m. And we are told that the mode number is going to be 150,000 modes. And we also know that the speed of light which will come to use for us is three times 10 to the eight m per second. Now, we are tasked with finding what is going to be the wavelength and the frequency of our E D F L. So let's go ahead and start out with our frequency here. Well, we actually have a formula for this. We have the speed of light times our mode number divided by two times the cavity length. So let's go ahead and plug in our numbers. We have three times 10 to the eighth times 150,000 divided by two times 20.48. When you plug this into your calculator, we get 4.69 times 10 to the 13th Hertz. Wonderful. So now let's go ahead and find our wavelength. Another simple formula for this, we have two times the cavity length divided by the mode number. So this is two times 0.48 divided by 150,000, which gives us 6.4 times 10 to the negative six m or 6.4 micrometers. So now we have found both the frequency and wavelength of our laser admitted by the E D F L which corresponds to our answer. choice of a. Thank you all so much for watching. I hope this video helped we will see you all in the next one.