Vertical cavity surface emitting laser device with monolithically integrated photodiode

A vertical cavity surface emitting laser (VCSEL) device, the VCSEL device comprising:

• an optical resonator;
• a photodiode;
• and an electrical contact arrangement, wherein the optical resonator comprises:
• a first distributed Bragg reflector;
• a second distributed Bragg reflector;
• and an active region for light emission, wherein the active region is arranged between the first distributed Bragg reflector and the second distributed Bragg reflector, wherein the photodiode comprises a light absorption region arranged in the optical resonator, wherein the electrical contact arrangement is arranged to provide an electrical drive current to electrically pump the optical resonator, and to electrically contact the photodiode, wherein the active region comprises at least one InxGa1-xAs layer, wherein 0≤x<1, wherein the light absorption region comprises at least one InyGa1-yAs layer, wherein 0<y<1, wherein y is greater than x, wherein the at least one InyGa1-yAs layer of the light absorption region is an intrinsic layer of the light absorption region, wherein the at least one InyGa1-yAs layer of the light absorption region has a thickness in a range from 15 nm to 50 nm, wherein the light absorption region of the photodiode comprises at least one undoped further layer based on a material different from the at least one InyGa1-yAs layer, wherein the at least one InyGa1-yAs layer is immediately adjacent to the further layer, and wherein an intrinsic zone of the light absorption region has a total thickness of at least 70 nm.