Semiconductor laser apparatus for optical head

A semiconductor laser aparatus for use for an optical head having a stem, a substrate mounted on said stem, a semiconductor laser chip provided on said substrate, photodetector means and a cap with a window glass mounted on said stem to hermetically seal said substrate, said laser chip and said photodetector means, comprising:

• a beam splitter attached to said substrate and having a first surface inclined at a predetermined angle with respect to a radiant surface of said laser chip in order to reflect a beam radiated from said laser chip toward said window glass to thereby direct said beam to an objective lens of an optical head, and said photodetector means formed on said substrate and covered by said beam splitter so as to receive the return beam reflected back through said objective.