Hybrid illumination system having a blue laser diode, dichroic mirror and yellow transmissive phosphor converter for generating white light

A headlamp, comprising:

• a first blue light source to provide a first blue light beam, wherein the first blue light source is a blue laser light source, and the first blue light beam is a blue laser light beam;
• a collimating lens, optically coupled to the first blue light source, to collimate the first blue light beam into a collimated blue light beam;
• an optical diffuser, optically coupled to the collimating lens, to optically homogenize the collimated blue light beam into a top hat spatially distributed beam;
• a transmissive yellow phosphor converter to convert the top hat spatially distributed beam into a phosphor-emitted light beam having a same direction as the top hat spatially distributed beam, wherein most of the phosphor-emitted light beam is yellow light converted from blue light of the top hat spatially distributed beam;
• condensing and collimating lenses, optically coupled to the yellow phosphor converter, to condense and collimate the phosphor-emitted light beam into a condensed and collimated phosphor-emitted light beam;
• a dichroic mirror, optically coupled to the condensing and collimating lenses, to filter the condensed and collimated phosphor-emitted light beam into a dichroic-filtered light beam passed by the dichroic mirror, the dichroic mirror configured to pass yellow light and to reflect at least some blue light;
• and
• a second blue light source, optically coupled to the dichroic mirror, to provide a second blue light beam, the dichroic mirror configured to reflect the second blue light beam in a same direction as the dichroic-filtered light beam to generate a white light beam;
• a spatial light modulator to modulate the white light beam at a pixel level to generate an image;
• illumination optics, optically coupled to the dichroic mirror, to receive and arrange the white light beam to illuminate the spatial light modulator;
• and
• projection optics, optically coupled to the spatial light modulator to receive the image, map pixels of the image to pixels of a larger image, and project the larger image at a distance away from the headlamp.

A method of generating a white light beam in an illumination apparatus, the method comprising:

• providing a first blue light beam, wherein the first blue light beam is a blue laser light beam;
• with a collimating lens, collimating the first blue light beam into a collimated blue light beam;
• with an optical diffuser, optically homogenizing the collimated blue light beam into a top hat spatially distributed beam;
• with a transmissive yellow phosphor converter, converting the top hat spatially distributed beam into a phosphor-emitted light beam having a same direction as the top hat spatially distributed beam, wherein most of the phosphor-emitted light beam is yellow light converted from blue light of the top hat spatially distributed beam;
• condensing and collimating the phosphor-emitted light beam into a condensed and collimated phosphor-emitted light beam;
• with a dichroic mirror, filtering the condensed and collimated phosphor-emitted light beam into a dichroic-filtered light beam passed by the dichroic mirror, the dichroic mirror configured to pass yellow light and to reflect at least some blue light;
• providing a second blue light beam;
• and
• with the dichroic mirror, reflecting the second blue light beam in a same direction as the dichroic-filtered light beam to generate the white light beam.