Cryogenic probe card

1. A cryogenic testing system, comprising:

a cryostat chamber configured to maintain a sample at temperatures below a threshold temperature, wherein the sample includes a two-dimensional array of components to be tested, the two-dimensional array comprising a first number (n) of columns and a second number (m) of rows;

a probe card, comprising:

a set of n column connectors configured to couple to respective columns of the two-dimensional array; and

a set of m row connectors configured to couple to respective rows of the two-dimensional array; and

a cryogenic connector for communicatively coupling the probe card to a processing unit outside of the cryostat chamber;

wherein the probe card is configured to:

selectively test individual components on the sample via row and column multiplexing; and

output readout data to the processing unit via the cryogenic connector; and

wherein the cryogenic connector has less than n×m communication lines leaving the cryostat chamber.

2. The cryogenic testing system of claim 1 , further comprising the processing unit, communicatively coupled by the cryogenic connector to the probe card; and

wherein the processing unit is configured to selectively test the individual component on the sample by addressing a corresponding row and column on the two-dimensional array.

3. The cryogenic testing system of claim 1 , wherein components within each row of the two-dimensional array are coupled to one another on the sample.

4. The cryogenic testing system of claim 1 , wherein the components to be tested comprise a plurality of light detectors.

5. The cryogenic testing system of claim 4 , further comprising an optical source configured to provide light to the plurality of light detectors within the cryostat chamber.

6. The cryogenic testing system of claim 5 , wherein the optical source is configured to provide the light to the plurality of light detectors without use of a movable probe.

7. The cryogenic testing system of claim 5 , further comprising a mount having a cold head within the cryostat chamber for mounting the sample, the mount including an aperture.

8. The cryogenic testing system of claim 7 , wherein the optical source comprises a single optical fiber positioned and configured to convey light through the aperture to the plurality of light detectors.

9. The cryogenic testing system of claim 5 , wherein the optical source is configured to provide light to all of the light detectors and wherein the probe card is configured to selectively readout data from individual light detectors of the plurality of light detectors.

10. The cryogenic testing system of claim 1 , wherein the first number (n) is different than the second number (m).

11. The cryogenic testing system of claim 1 , wherein the threshold temperature is less than 10 Kelvin.

12. The cryogenic testing system of claim 1 , wherein the processing unit is maintained at temperatures above the threshold temperature.

13. The cryogenic testing system of claim 1 , wherein the probe card is configured to output readout data from a sequence of the individual components on the sample without use of moving parts.

14. The cryogenic testing system of claim 1 , wherein the probe card is configured to output readout data from the sample without use of active switches.

15. The cryogenic testing system of claim 1 , wherein the sample comprises a superconducting chip.

16. A method, comprising:

maintaining a sample at temperatures below a threshold temperature within a cryostat chamber, the sample having a plurality of components arranged in a two-dimensional array; and

while maintaining the sample at the temperatures below the threshold temperature:

testing an individual component of the plurality of components by utilizing a first connector coupled to a first row of the sample and a second connector coupled to a first column of the sample, wherein the individual component is within the first row and the first column; and

outputting a test result of testing the individual component to a processing unit arranged outside of the cryostat chamber.

17. The method of claim 16 , wherein the individual component comprises a light detector;

the method further comprises providing light to the light detector; and

wherein testing the individual component comprises obtaining test data corresponding to the light detector receiving the provided light.

18. The method of claim 16 , wherein the sample comprises a superconducting chip.

19. The method of claim 16 , wherein the two-dimensional array comprises a first number (n) of columns and a second number (m) of rows;

wherein components within each row of the two-dimensional array are coupled to one another on the sample;

wherein testing the individual component of the plurality of components comprises utilizing a cryogenic probe card to test the individual component; and

wherein the cryogenic probe card comprises:

a set of n column connectors configured to couple to respective columns of the two-dimensional array; and

a set of m row connectors configured to couple to respective rows of the two-dimensional array.