Q 01/05

In the acronym 'laser', what do the letters S and E stand for?

A) Single-frequency emission

B) Stimulated emission

C) Spectral energy

D) Solid-state excitation

Answer · why

B) Stimulated emission

Stimulated emission: a passing photon triggers an excited atom to release an identical photon, so light bouncing between two mirrors multiplies in per...

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

Theodore Maiman: when the feat was announced in July 1960, one Los Angeles newspaper headlined it as the discovery of a science-fiction death ray.

Q 03/05

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

A) Topaz

B) Ruby

C) Emerald

D) Diamond

Answer · why

B) Ruby

Ruby: a leading laser theorist had publicly said pink ruby would take too much energy to work as a laser, yet a flash-lit pink ruby rod gave off the f...

Q 04/05

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

A) Infrared

B) Microwaves

C) X-rays

D) Ultraviolet

Answer · why

B) Microwaves

Microwaves give the maser its M, and the name 'laser' was made simply by swapping that first word for 'light'.

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

Albert Einstein worked out the idea more than 40 years before anyone built a laser, and his own Nobel Prize honoured quite different work, on the phot...