Reducing audio noise in a lidar scanner with a polygon mirror

A lidar system comprising:

• a light source configured to emit light;
• a receiver configured to detect the light scattered by one or more remote targets;
• and
• an optical scanner including:
• a rotatable polygon mirror comprising:
• a block having a first wall, a second wall, and a plurality of reflective surfaces extending between the first and second walls, the reflective surfaces being angularly offset from one another along a periphery of the block,
• a polygon mirror axle extending into the block through at least one of the first and second walls, about which the block rotates,
• a motor driving rotation of the block, and
• a plurality of chamfered corners in the block, each of the chamfered corners being bounded by a pair of adjacent reflective surfaces and the second wall, and not bounded by the first wall, the optical scanner further including:
• a second mirror pivotable along an axis orthogonal to the polygon mirror axle and more proximate to the second wall of the block than the first wall of the block.