Theory 18/Nanoscale/Nanowire lasers
Lasing Needs Gain Length
The claim
The threshold of a nanowire laser is set by the ratio of cavity length to gain length, so a short wire needs a better material to lase.
01Mechanism
Round-trip gain must exceed loss; the ratio determines whether the mode reaches threshold.
02Prediction
Threshold should track the ratio.
03Refutation
Threshold tracking material quality alone would remove cavity length.