Standards for testing

Overview

Standards for testing are intended to cover automated measurements of photonic integrated circuits (PICs). They are meant to be applicable for both testing (pass/fail-type of measurements) and characterization (through investigation of PIC performance).

The standards comprise of two different views on PIC design, each containing only relevant information for it purpose (CDF and netlist), measurement description format, and a standard instrument API.

The test standards enable two novel techniques in PIC testing: test-as-a-service and virtual testing.

  • Test-as-a-service is an approach in which a test house is able to perform PIC testing by using descriptions provided by the PIC designer in the form of CDF and MDF. This is also called as a labless approach to PIC design.

  • Virtual test bench methodology implies that the same set of scripts can be run on both real measurement setup and a circuit simulator with virtual instruments emulating measurements. To enable this, a PIC netlist is use by the circuit simulator, the test sequence has to be represented in the form of MDF, and all instruments (actual and virtual) should adhere to the same API.

Chip Description File

When testing a PIC, full detailed chip layout is not actually needed, moreover, it might not be available due to IP reasons. Only information about a limited amount of features is relevant. They include PIC size, identification, locations of electrical and optical IOs (pads and ports), and fiducials. Chip Description File format is a way of representing this data in a simple and clear way.

See more details on openEPDA CDF format.

PIC netlist format

When performing circuit simulations, PIC schematic is essential. This is contrast with measurement of an actual PIC discussed above. PIC netilst is a representation of PIC schematic, which includes used components, connections between them, and necessary physical layout information, e.g. shapes of the interconnects.

The netlist format is currently under development.

Measurement Description File

Measurement description defines the test sequence, test parameters, locations, etc. In short, it determines which DUTs to measure, and what exactly to measure.

See more details on openEPDA MDF format.

Equipment API

In order to make test procedures description independent of actual test equipment brands and models, we have defined an API for instruments used in PIC testing. Having the API also makes it possible to create virtual test benches with equipment emulators able to execute the same test sequences as the actual test setups.

The equipment API is currently under development.