Laser diode and sonar: what they have in common
- Step 1. Laser diode — is a kind of — Laser. A semiconductor laser.
- Step 2. Laser — has part — Mirror. A resonator made of mirrors.
- Step 3. Mirror — is part of — Periscope. Mirrors or prisms.
- Step 4. Periscope — is part of — Submarine. A periscope.
- Step 5. Submarine — has part — Sonar. Underwater acoustics.