Patent ID: 8184522

Claim:
An optical head for recording and/or reproducing a signal on a multi-layer optical recording medium, the optical head comprising: a light source that emits light of less than or equal to 450 nm wavelength; an objective lens that condenses light emitted from said light source onto the multi-layer optical recording medium; and a light separator that is disposed between said light source and said objective lens on a light path of the emitted light and separates the emitted light from reflected light which is emitted from said light source and reflected by the multi-layer optical recording medium, wherein said light separator includes: a first glass; a multilayer film that is formed on said first glass; an adhesive layer that is arranged on said multilayer film; a second glass that is fixed on said multilayer film by an adhesive bonding provided by said adhesive layer; the emitted light emitted from said light source enters and transmits through said first glass and transmits through said first glass again after a reflection on said multilayer film, in which approximately 90% or more of the emitted light is reflected on the multilayer film, and thereby the emitted light exits said light separator; and the reflected light reflected by the multi-layer optical recording medium enters said light separator from a side of said first glass and transmits through said light separator in an order from said first glass, said multilayer film, said adhesive layer, to said second glass.