Q 01/05

The word 'laser' began as an acronym. What does the 'S' and 'E' part stand for?

A) Single-frequency emission

B) Stimulated emission

C) Spectral energy

D) Solid-state excitation

Answer · why

B) Stimulated emission

The full phrase is 'light amplification by stimulated emission of radiation'; a joker once noted 'LOSER' (light oscillation) would be more accurate.

Q 02/05

Who built the first working laser, in 1960?

A) Gordon Gould

B) Charles Townes

C) Theodore Maiman

D) Arthur Schawlow

Answer · why

C) Theodore Maiman

He did it at Hughes Research Laboratories in Malibu, beating rival teams at Columbia, Bell Labs and TRG.

Q 03/05

The first working laser used a synthetic crystal of which gemstone as its lasing medium?

A) Sapphire

B) Ruby

C) Emerald

D) Diamond

Answer · why

B) Ruby

A flashlamp pumped the crystal to produce red light at 694 nanometres, in pulses only.

Q 04/05

The maser, the laser's predecessor, amplified what kind of radiation?

A) Radio waves

B) Microwaves

C) X-rays

D) Ultraviolet

Answer · why

B) Microwaves

Early lasers were briefly called 'optical masers' before 'microwave' was swapped for 'light' in the acronym.

Q 05/05

Which physicist laid the theoretical foundations for the laser in a 1917 paper on the quantum theory of radiation?

A) Albert Einstein

B) Max Planck

C) Werner Heisenberg

D) Niels Bohr

Answer · why

A) Albert Einstein

His coefficients for absorption, spontaneous emission and stimulated emission are still called Einstein coefficients.