Optical system to obtain uniform illumination from diode laser

Claim 3

In a junction diode laser and optical system having an emitting wavelength in the nanometer range and an elliptical shaped beam, the beam divergence being about 20 degrees perpendicular to the junction and 10 degrees parallel to the junction, and having Gaussian intensity distribution; the improvement for correcting the Gaussian beam intensity distribution to flat distribution, using all spherical lens elements, which comprises: a first graded index of refraction lens collimating the diode beam; a beam shaper receiving the collimated beam from said graded index rod lens, producing a round beam from the elliptical diode beam; a second graded index of refraction lens receiving the round beam from said beam shaper and producing a beam focused to a convergence point; a Gaussian beam corrector and collimator consisting of: a compound lens including a meniscus lens receiving the beam from said second graded index rod lens from the convergence point and expanding the beam; a second compound lens, including a meniscus lens and an objective lens, receiving the expanded beam from said first compound lens; whereby the converged beam compensates aberration introduced by beam shaping, the first compound lens expands the beam and the second compound lens emits an expanded, collimated beam having uniform intensity distribution.

Claim 4

In a junction diode laser and optical system having an emitting wavelength in the nanometer range and an elliptical shaped beam, the beam divergence being about 20 degrees perpendicular to the junction and 10 degrees parallel to the junction, and having Gaussian intensity distribution; the improvement for correcting the Gaussian beam intensity distribution to flat distribution, using all spherical lens elements, which comprises: a first graded index of refraction lens collimating the diode beam; a beam shaper receiving the collimated beam from said graded index rod lens, producing a round beam from the elliptical diode beam; a second graded index of refraction lens receiving the round beam from said beam shaper and producing a beam focused to a convergence point; a Gaussian beam corrector and collimator consisting of: a compound lens including a meniscus lens receiving the beam from said second graded index rod lens from the convergence point and expanding the beam; a second compound lens, including a meniscus lens and an objective lens, receiving the expanded beam from said first compound lens; whereby the converged beam compensates aberration introduced by beam shaping, the first compound lens expands the beam and the second compound lens emits an expanded, collimated beam having uniform intensity distribution.

Claim 5

The improvement in a junction diode laser as described in claim 2, wherein the elliptical to circular beam shaper consists of: a graded index lens passing and collimating the elliptical beam having an ellipse major axis and a minor axis; a prism receiving the collimated elliptical beam major axis along the hypotenuse of said prism, and producing a circular beam.

Claim 6

The improvement in a junction diode laser as described in claim 2, wherein the Gaussian beam corrector and collimator consisting of: a compound lens including a meniscus lens receiving the beam from a 20 degree divergent source and having a meniscus radius of 3 to 5 mm, for expanding the beam; and a second compound lens including a meniscus and an objective lens receiving the expanded beam from said compound lens and emitting an expanded, collimated beam having uniform intensity distribution; whereby any source having a 20 degree divergent Gaussian distributed intensity beam is converted to a collimated, uniform intensity beam.

Claim 7

The improvement in a junction diode laser as described in claim 2, wherein the first graded index of refraction lens collimating the diode beam is focused to a plane 0.4 to 0.6 of the maximum beam intensity, wherein the Gaussian beam is near uniform.

Claim 8

The improvement in a junction diode laser as described in claim 2, wherein the first graded index of refraction lens collimating the diode beam is focused at the diode junction.

Claim 9

The improvement in a junction diode laser as described in claim 2, wherein the beam corrector first compound lens meniscus has a radius 3 to 5 millimeters, and the angle of divergence of the laser beam is 20 degrees from axial and at a focal point distance of 5 to 7 mm from the meniscus surface.

Claim 10

The improvement in a junction diode laser as described in claim 2, in combination with a light modulator located in light communication with the objective lens, whereby the laser frequency is modulated and heterodyned by a local oscillator frequency.

Claim 11

The improvement in a junction diode laser as described in claim 2, further comprising electrical modulator means for electrically modulating the laser diode at frequencies including the range from DC to Gigahertz.