1 / 7

LASER s

LASER s. L ight A mplification by S timulated E mission of R adiation. Function. Produce an intense beam of light at a very narrow bandwidth (0.01 nm) that is highly coherent Useful in spectroscopy Specificity High sensitivity Small detection window. Components. Power Supply

conway
Télécharger la présentation

LASER s

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. LASERs Light Amplification by Stimulated Emission of Radiation

  2. Function • Produce an intense beam of light at a very narrow bandwidth (0.01 nm) that is highly coherent • Useful in spectroscopy • Specificity • High sensitivity • Small detection window

  3. Components • Power Supply • Pumping Source • Laser media • Mirrors

  4. Mechanism of Action • Power Supply turns on the pumping source • Pumping Source emits radiation that is absorbed by laser media • Intensity of pumping source produces a population inversion • Stimulated emission becomes the dominant process

  5. continued • Stimulated emission – one photon is “absorbed” by excited electron and two coherent photons are emitted. • Coherent photons that happen to travel along the horizontal path between the two mirrors are selectively amplified (photon traveling at different angles deviate from the path between the two mirrors and are lost

  6. 3 and 4 level systems are most common because it is easier to reach a population inversion En NR (fast) En Non-radiative NR (fast) Ey Ey Ex NR (fast) E0 E0

  7. Types • Solid State • Nd:YAG laser; 1064 nm (freq doubled) • Gas lasers • He/Ne, CO2, N2, eximer (ArF+) • Dye Laser • Fluorescent dye solutions, tunable (20-50 nm) • Organic compounds capable of fluorescing in the UV, visible, and IR regions • Semiconductor Diode Lasers • LEDs; Not used much in spectroscopy, as of yet.

More Related