Industrial Laser Design

Question 1

What does LASER stand for?

Answer 1

Light Amplified by the Stimulated Emission of Radiation

Question 2

Describe the workings of a laser internally?

Answer 2

Energy source excites the atoms in an active medium, different wavelengths emitted in all directions from electrons jumping back to lowest energy level, totally reflecting back mirror bounces light to partially reflecting front mirror, light is ampified as it bounces back and forward and an amount is emitted as a laser beam.

Question 3

Explain the basis of a gas laser?

Answer 3

Active medium is gas (agron, krypton, CO2, excimer)

Safety - heavy, gas may be hazardous, high voltages and temps., connections

Question 4

Explain the basis of a dye laser?

Answer 4

Active medium is a liquid that can be made to lase.

Different dyes - different laser colours

Safety - dyes usually toxic, containing liquid, potential mix with high voltages

Question 5

Explain the basis of a diode laser?

Answer 5

Small semiconductor chips, usually used in a laser pointer, may have internal batteries

Safety - small but high power, invisible beams

Question 6

Explain the basis of a solid state laser

Answer 6

Active medium is a solid eg. crystal, excited by a light source (like an Nd:YAG)

Question 7

What are the main differences between laser types?

Answer 7

• Laser discharge medium
• Excitation mechanism
• Laser beam conditioning
• Manual and automatic control

Question 8

What are the advantages of fibre lasers?

Answer 8

• Light already coupled into a flexible fibre
• Can be several kilometres long
• High optical quality
• More compact
• High vibrational stability and extended lifetime, due to lack of external cavity
• High peak power and nanosecond pulses for effective engraving

Question 9

Describe Q-Switching

Answer 9

Quality switching - electrically operated optical switch which stops lasing action, energy builds up in higher energy levels, means very short and high power pulses can be released.