Disclosed are a planar wave guide type optical amplifier for amplifying a light signal passing through an optical fiber, a method of manufacturing the above light amplifier, and a laser oscillator using the light amplifier, The planar wave guide type optical amplifier comprises a first core formed to...http://www.google.de/patents/US5381262?utm_source=gb-gplus-sharePatent US5381262 - Planar wave guide type optical amplifier
