Laserlabreport - 1 Measure Laser Cavity Length 62 cm Quartz...

Info icon This preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
1. Measure Laser Cavity Length – 62 cm Quartz window to mirror – 10.5 cm Tr = roundtrip time of laser cavity = frequency at which laser pulses are produced (2 62 cm ) + (2 10.5 cm ) =145 cm The round trip time for intracavity light = 145 cm 1 m 100 cm 1 3 10 8 m s 100 cm 1 m = 4.83 10 - 7 cm s In our first attempt, we first start to see light at 13000 Volts - Spontanious emmission Stimulated Emission - 14000 Volts (to get the spark across the nitrogen) Monday’s Data: Spontaneous Emission: 7 kV Stimulated Emission: 20 kV 2. Spontaneous Emission because it is not focused, not coherent. Stimulated emission on inside, focused center of the beam. Spontaneous emission on outside edges of the beam. That is when you actually get a laser. That is the voltage it takes to completely break down the Nitrogen in the laser cavity. There are many possible applications for a pulsed nitrogen laser. One possible application is using the laser to learn about properties of light and nitrogen. For example, the speed of light can be calculated from data obtained from the laser. The emission spectrum of nitrogen can also be determined since only frequencies in the emission spectrum can be produced. This laser is particularly good for making such measurements because although it is still dangerous, it is very low power and does not generate a significant amount of heat. The nitrogen laser can also be used as a power source for other lasers. The nitrogen laser can be used to pump a dye laser and in other applications where a UV pulse is needed, like UV spectroscopy. The nitrogen laser uses nitrogen as the lasing medium. The laser consists of a chamber filed with nitrogen at near atmospheric pressure. It also has two electrodes that form a spark gap inside. Unlike most lasers, no mirrors are needed due to the nitrogen's high gain as a lasing medium, but one mirror is sometimes used to increase beam intensity. When a 20kV+ electric pulse is sent over the gap, the resulting spark will give off a pulse of UV light. This light stimulates the nitrogen to send out more UV light, this forms a nanosecond pulse with UV light (peak wavelength 337nm). When the mirror is turned, it is like seeing two separate images. It changes the shape of the laser light. The shape of the cavity is circular but the shape of the image is an ellipse, longer horizontally than the vertically. There are two hacksaw blades on either side of the cavity and the electrons (spark or lightning) arcs from one side to the other, making the shortest jump as possible.
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
How the laser works:
Image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern