Systems and methods for pixel on-off switching in focal plane arrays
Systems and methods are described for optical processing. According to some aspects an optical processing apparatus may include a pixelated photodiode array (PDA), each pixel in the PDA includes a radiation detector. The apparatus also includes a read out integrated circuit (ROIC) that includes a logic circuit and a plurality of switch elements. The plurality of switch elements being switchable between an armed state for arming its corresponding radiation detector and transmitting a signal received from the corresponding detector to the ROIC, and a disarmed state for disarming its corresponding detector and blocking transmittal of the signal, wherein in the armed state, the PDA is configured to detect an incoming optical signal and in the disarmed state, the PDA is configured to disregard the incoming optical signal. Moreover, the logic circuit controls a switch state of a selectable switch element associated with a radiation detector.
1. An apparatus comprising:
a pixelated photodiode array (PDA), wherein each pixel in the PDA includes a radiation detector;
a read out integrated circuit (ROIC) comprising:
a plurality of switch elements each being connected to a respective radiation detector of each pixel, each switch element of the plurality of switch elements being switchable between an armed state for arming its corresponding radiation detector and receiving an output signal from its corresponding detector, and a disarmed state for disarming its corresponding radiation detector and blocking the output signal, wherein in the armed state, the PDA is configured to detect an incoming optical signal and in the disarmed state, the PDA is configured to disregard the incoming optical signal, and
a logic circuit configured to control a switch state of each switch element of the plurality of switch elements; and
a circuit fuse configured to electrically disengage each respective radiation detector,
wherein the circuit fuse comprises a pair of transistors configured to control a voltage across the circuit fuse, and
wherein the logic circuit is further configured to apply a predetermined voltage to the pair of transistors, and the predetermined voltage causes the fuse to burn out and create a permanent open circuit between the PDA and the ROIC.
2. The apparatus of claim 1 , wherein the logic circuit is further configured to:
arm the PDA, and
place a first switch element of the plurality of switch elements associated with a first radiation detector in the disarmed state in response to detecting a faulty operation of the radiation detector.
3. The apparatus of claim 1 , wherein the PDA comprises one or more Geiger-mode avalanche photodiodes (GmAPDs).
4. The apparatus of claim 3 , wherein the logic circuit is further configured to:
place a first switch element of the plurality of switch elements associated with a first radiation detector in the disarmed state by applying a net reverse voltage value below a detected breakdown voltage of the one or more GmAPDs.
5. The apparatus of claim 4 , wherein the logic circuit is further configured to:
place a second switch element of the plurality of switch elements associated with a second radiation detector in the armed state by increasing a reverse voltage value to a bias level above a detected breakdown voltage of the one or more GmAPDs, the first and second switch elements being different.
6. The apparatus of claim 1 , wherein the logic circuit is further configured to:
determine an operation status of each respective radiation detector, wherein the determined operation status corresponds to a stored select/deselect mapping for each respective radiation detector.
7. The apparatus of claim 6 , wherein the operation status corresponds to an observed dark current value above a predetermined dark current threshold value.
8. The apparatus of claim 6 , wherein the operation status corresponds to an observed noise level above a predetermined noise threshold value.
9. The apparatus of claim 6 , wherein the operation status corresponds to an observed leakage current level above a predetermined leakage current threshold value.
10. The apparatus of claim 1 , wherein the circuit fuse is configured to electrically disengage each respective radiation detector in response to an operation of the radiation detector being associated with an observed leakage current above a predetermined leakage current threshold.
11. The apparatus of claim 10 , wherein the circuit fuse is incorporated within the ROIC.
12. The apparatus of claim 1 , wherein the logic circuit is further configured to apply the predetermined voltage in response to the observed leakage current being above the predetermined leakage current threshold.
13. A method comprising:
receiving an optical signal at a pixelated photodiode array (PDA);
arming, by a logic circuit, a radiation detector of a pixel of the PDA by controlling a selectable switch element of a read out integrated circuit (ROIC) connected to the PDA to power the radiation detector and transmit a received output signal of the radiation detector; and
disarming, by the logic circuit, the radiation detector of the pixel of the PDA by controlling the selectable switch element to disconnect the radiation detector from power and to block the radiation detector from outputting the signal; and
permanently disengaging, using a circuit fuse, a radiation detector associated with a detected operation,
wherein the circuit fuse comprises a pair of transistors configured to control a voltage across the circuit fuse, and
wherein the logic circuit is further configured to apply a predetermined voltage to the pair of transistors, and the predetermined voltage causes the fuse to burn out and create a permanent open circuit between the PDA and the ROIC.
14. The method of claim 13 , further comprising:
disarming the radiation detector by applying a net reverse voltage value below a detected breakdown voltage of the radiation detector.
15. The method of claim 13 , further comprising:
arming the radiation detector by increasing a reverse voltage value to a bias level above the breakdown voltage of the radiation detector.
16. The method of claim 13 , wherein the detected operation is a faulty operation of the radiation detector.