Laser light source for laser projector

Abstract

The invention discloses a laser light source special for a laser projector. The laser light source comprises a laser emitting part (1-3) and a feedback interference system, wherein the feedback interference system comprises a phase modulator (5), a polarizing beam splitter (6) and a reflecting mirror (7) which are arranged along the light path in turn; the laser beam emitted from the laser emitting part (1-3) is a linearly polarized light which enters into the phase modulator (5); the phase difference is generated for the phases of a P polarized light component and an S polarized light component in the laser beam by the phase modulator (5), so that the polarization state of the laser beam is changed; the laser beam outputted from the phase modulator (5) enters into the polarizing beam splitter (6); the P polarized light component of the laser beam is transmitted to the reflecting mirror (7) by the polarizing beam splitter (6) and is reflected to the polarizing beam splitter (6) by the reflecting mirror (7); after the P polarized light component is transmitted, the P polarized light component returns to the laser emitting part (1-3) through the phase modulator (5); the S polarized light component of the laser beam is reflected by the polarizing beam splitter (6).

Description

technical field [0001] The present application relates to a laser light source, in particular to a laser light source dedicated to a laser projector. Background technique [0002] With its high power, long life, and high degree of color reproduction, the three-color laser has attracted more and more attention, and has become the preferred light source for the next generation of projection display. At present, laser projectors use red, green and blue laser semiconductor (LD) arrays, which enter the projection unit through optical fibers or coupling lens systems to form a laser projection system. Due to its good coherence, the semiconductor laser will have strong speckle phenomenon on the projection screen, so it cannot be directly used as a projection light source. The current measures are to use elements such as phase plates or scattering plates to disturb its polarization state and phase, and reduce its coherence. These measures can only reduce the granularity and thicknes...

AI Technical Summary

Problems solved by technology

The measures taken now are to use components such as phase plates or scattering plates to disturb its polarization state and phase, and reduce its coherence. These measures can only reduce the granularity and thickness of speckle, but cannot fundamentally eliminate speckle.

The laser projectors we produced through the above methods can be used in engineering projects, but they are not suitable for civilian use (people need to watch them repeatedly for a long time)

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