or more photodiode n p n type it will be recognized by those of ordinary skill in the art that single electron transistors set technologies can be deployed to intercept generated electron from absorption of photon in gaas and some other materials and then count them with a digital signal processor and like components the device is powered by a bias means interposed to bisect circuit trace 131 into a first segment 133 connecting negative or source electrode 130 to the negative pole of bias means 160 and a second segment 132 connecting the positive pole of bias means 160 to gate electrode 140 via a second segment 132 it should be appreciated that circuit segments 132 and 122 may both connect directly to gate electrode 140 or as shown in fig1 joint at junction 142 which then connects to gate electrode 140 via circuit segment 141 the first 115 and second 135 gaps are generally both smaller than the third gap 145 so that when a photon is absorbed by the direct semiconductor quantum dot 110 creating an electron hole pair the bias promotes tunneling of the electron to the drain electrode 120 this results in the hole remaining in the quantum dot 110 as the gate electrode 140 is in close proximity to the direct semiconductor 110 the electron being negatively charged flows to the gate electrode to balance the charge on the quantum dot 110 the detection circuit measures this change in current to count each photon incident.