Sony red mW / mA issue

[BlueFusion]

I am running a Sony 16x red at 300mA (heatsinked), which should be somewhere in the realm of 150mW, yet I am unable to light a sharpied red match. I had previously lit unsharpied red matches at 240mA, from 12V, whereas I am now at 300mA from 6V.
Is my diode dead or is it a voltage thing?

 

[phenol]

I am running a Sony 16x red at 300mA (heatsinked), which should be somewhere in the realm of 150mW, yet I am unable to light a sharpied red match. I had previously lit unsharpied red matches at 240mA, from 12V, whereas I am now at 300mA from 6V.
Is my diode dead or is it a voltage thing?

what is the voltage across the LD at 300mA? its performance is probably beginning to deteriorate, as 300mA are a lot... :. Maybe its behaviour corresponds to figure b below.

 

[flogged]

I am running a Sony 16x red at 300mA (heatsinked), which should be somewhere in the realm of 150mW, yet I am unable to light a sharpied red match. I had previously lit unsharpied red matches at 240mA, from 12V, whereas I am now at 300mA from 6V.
Is my diode dead or is it a voltage thing?

One thing to check is to make certain the diode is centered correctly in the casing. If the diode is not on axis with the optical path this will prevent you from getting a tight spot at focus for burning.