Patent ID: 8830587

Claim:
An apparatus for providing a pump light of a first wavelength λ 1 to a laser that emits a second wavelength λ 2 , comprising: a first laser of the first wavelength λ 1 that is energizable to direct light along a first axis in a first direction; a second laser of the first wavelength λ 1 that is energizable to direct light along a second axis parallel to the first axis, wherein the first and second axes define a first plane P 1 ; and a filter apparatus that is disposed to form a composite light beam of the first wavelength λ 1 , the filter apparatus formed on a transparent body that is disposed in the path of the directed light and having: (i) a first filter that is formed on a first surface of the filter apparatus that is disposed at an oblique angle to the first and second axes and that is transmissive to λ 1 and reflects λ 2 ; (ii) a second filter that is formed on a second surface of the filter apparatus that is parallel to the first surface, wherein the second filter reflects λ 1 and transmits λ 2 ; (iii) a third filter that is formed on the first surface of the filter apparatus, coplanar with the first filter, and wherein the third filter reflects λ 1 and transmits λ 2 ; wherein the filter apparatus re-aligns the first and second axes along a second plane P 2 that is orthogonal to P 1 and parallel to the first direction.