A.強度為I的線偏振光; B..強度為I/2的線偏振光; C.強度為I的自然光; D.強度為I/2的自然光;
A.β=-2× B.β=-1/2× C.β=1/2× D.β=2×
A.∞; B.-∞; C.200mm; D.–200mm;