光こう路ろ長ちょうこうろちょうMeanings1nounoptical path lengthphysicsTechnical term in physics; the product of geometric path length and refractive index.光こう路ろ長ちょうの差さが干かん渉しょう縞じまのパターンを決きめる。The difference in optical path length determines the interference fringe pattern.
