Power monitoring approach for VCSELS and VCSEL arrays

A VCSEL device comprising:

• a VCSEL chip, the VCSEL chip having a center point and a top surface, and
• a photodiode, the photodiode having a center point, wherein the VCSEL chip and the photodiode arranged on a submount such that the center point of the VCSEL chip is separated from the center point of the photodiode by a first distance;
• and
• wherein the VCSEL chip and photodiode are housed in a package, the package having:
• a window configured and arranged to allow light emitted from the VCSEL chip to pass through the window, the window having a first lateral end and a second lateral end;
• a spacer arranged between the submount and the window;
• and
• a pseudo-random, non-periodic diffuser provided extending from the first lateral end to the second lateral end, the non-periodic diffuser being arranged at a height of a second distance above the top surface of the VCSEL chip, wherein the second distance is less than the first distance;
• wherein light emitted by the VCSEL chip travels in three manners:
• a portion of the light propagates is transmitted through the diffuser and through the window;
• a first minority portion of the light is repeatedly scattered and reflected within the diffuser parallel to a plane of the window;
• and
• a second minority portion of the light is scattered by the diffuser back into the package and to the photodiode.

A VCSEL device comprising:

• a VCSEL chip, the VCSEL chip having a center point and a top surface, and
• a photodiode, the photodiode having a center point, wherein the VCSEL chip and the photodiode arranged on a submount such that the center point of the VCSEL chip is separated from the center point of the photodiode by a first distance;
• wherein the VCSEL chip and photodiode are housed in a package, the package having:
• a window configured and arranged to allow light emitted from the VCSEL chip to pass through the window;
• a spacer arranged between the submount and the window;
• and
• a diffuser arranged on a surface of the window and extending over a majority of the surface, and being arranged at a height of a second distance above the top surface of the VCSEL chip, wherein the second distance is less than the first distance,
• wherein light emitted by the VCSEL chip travels in three manners:
• a portion of the light is transmitted through the diffuser and through the window;
• a portion of the light is repeatedly scattered and reflected within the diffuser parallel to a plane of the window;
• and
• a portion of the light is scattered by the diffuser back into the package and to the photodiode.