mirrors - 2023 ACF Nationals

Question

Ursula Keller invented a type of these objects that adds a layer of saturable absorber on top of alternating layers of materials with different indices of refraction. For 10 points each:

[10e] Interferometers often use the “half-silvered” type of what objects as beam splitters? In Cassegrain and Newtonian telescopes, these objects have a parabola shape.

ANSWER: mirrors [accept reflectors or distributed Bragg reflectors or (semiconductor) saturable absorber mirrors; prompt on SESAMs or SAMs by asking “what does that stand for?”]

[10m] Passive mode locking replaces one of the mirrors in these devices with a saturable absorber mirror. These devices can use a ring-like arrangement of mirrors to avoid creating standing waves.

ANSWER: optical resonators [or optical cavities or resonating cavity or cavity resonator; prompt on lasers]

[10h] On the other hand, active mode locking uses one of these devices to periodically vary the intracavity loss. These devices usually operate by either an electro-optic or an acousto-optic physical mechanism.

ANSWER: modulators

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Summary


2023 ACF Nationals	04/22/2023	Y	20	13.00	90%	20%	20%

Data


Brown A	Claremont A	10	0	0	10
McGill A	Columbia A	10	0	10	20
Cornell B	Minnesota B	10	10	0	20
Duke A	Georgia Tech A	10	0	10	20
Vanderbilt A	Harvard A	10	0	0	10
Johns Hopkins A	North Carolina A	10	0	0	10
Rutgers B	Ohio State A	10	0	0	10
Penn A	Minnesota A	0	0	0	0
Illinois A	Penn State A	0	0	0	0
Chicago A	Rutgers A	10	0	10	20
Georgia Tech B	Stanford A	10	0	0	10
WUSTL A	Indiana A	10	0	0	10
Yale A	WUSTL B	10	0	0	10
Columbia B	Yale B	10	0	0	10
MIT A	Florida B	10	10	0	20
Houston A	Maryland A	10	0	0	10
Cornell A	UC Berkeley A	10	10	0	20
Florida A	Purdue A	10	10	10	30
Iowa State A	Imperial A	10	0	0	10
Toronto A	South Carolina A	10	0	0	10