Chapter 3 - Lasers Flashcards
What is Opthalmology?
Clinical and surgical practices related to the eye
What does laser stand for?
Light Amplification by Stimulated Emissions of Radiation
What is a mechanical wave and does it involve light?
Mechanical waves involve the periodic motion of particles in a medium. Light is NOT a mechanical wave because it can travel in both mediums and vacuums. Mechanical waves cannot travel in vacuums.
What two forces make up light?
Magnetic and Electric forces
What type of wave is light?
A transverse wave. (Two perpendicular waves that travel in the same direction)
How is the energy of light related to its wavelength
The energy of light is inversely proportional to its wavelength. (The shorter the wavelength, the more energy it is)
What is spontaneous emission?
When an electron absorbs energy through random occurrences and transitions back down to its ground state, releasing a photon.
What is stimulated emission?
When a photon that has the same energy as the energy difference between ground and excited state passes by an excited state electron and causes it to transition down to its ground state, emitting a photon.
What is population inversion?
When there is a higher amount of electrons in their excited state rather than the ground state.
What is pumping?
The process of putting electrons in a perpetually excited state
What is the active medium (aka lasing medium)?
The medium in which energy is pumped into that puts electrons in their excited state. Is often gas but could be solid or liquid.
What is the metastable state?
The state in which electrons stay in their excited energy state.
What is the optical resonating cavity?
A cavity consisting of a mirror on either side, one fully reflective, one partially. The lasing medium is placed inside.
What are the 5 most important characteristics of laser light?
- Monochromaticity
- Coherence
- Directionality
- Intensity
- Focusability
What are the three base components of a laser?
- Energy source (pump)
- Optical resonator (cavity)
- Gain medium
