Driving the development of high-speed networks and 5G, photonic integrated circuits (PICs) are a well-known technology in the telecom world—mainly thanks to the frantic development of transceivers and passive components that are smaller, faster, cheaper and greener than their bulk-optics counterparts. PICs are also getting traction—both from a commercial and research perspective—in other sectors too (e.g., lab-on-a-chip, LIDAR technology or quantum computing).
Through memberships in consortiums around the globe, such as AIM Photonics, EPIC and now LUX Photonics, EXFO has built strong partnerships with major vendors to offer integrated solutions in PIC testing.
With the rise of integrated photonics and the new challenges they bring forth, it can be tricky to keep up with evolving optical test requirements and to equip photonics labs accordingly for testing active (i.e., emitting light) or passive (i.e., guiding light) optical components . You may be asking yourself: what spectral testing capabilities should I be looking for right now or in the near future? Discover what EXFO has to offer.
Testing active components such as lasers and amplifiers found on PICs is quite straightforward.
An optical spectrum analyzer (OSA) can be used to perform tests on active components simply by connecting the light source or laser output to the OSA to get spectral signal of the sources, as seen below.
Industry-leading OSAs such as the OSA20 have the advantage of being very fast, performing up to five scans per second at speeds of 2000 nm/s, fast enough for real-time component alignment and with a high enough resolution to allow measurement of key parameters such as OSNR and SMSR.
Testing PIC-based passive component is even more challenging, due to the high port count of some components like arrayed waveguide grating (AWG) or the sheer number of components to test on a single die. A component test platform is a multiport detection system that operates in conjunction with a continuously tunable laser to measure optical insertion loss, return loss and polarization-dependent loss across the laser’s spectral range. The method yields optical spectrum quickly and with a high wavelength resolution, typically on the order of a picometer.
The CTP10 is a modular component test platform that characterizes the spectral properties of high port count devices in one single scan with picometer resolution and a 70 dB dynamic range , even when using the T100S-HP laser at 100 nm/s. The CTP10 operates from 1240 to 1680 nm and covers a wide range of applications, including telecom, sensing and LIDAR. Its electronics and internal processor make data transfer a breeze. The CTP10 can be remotely controlled using SCPI commands, facilitating integration as part of an automated PIC testing setup, increasing PIC testing throughput while reducing test time.
For the characterization of PIC components with a limited number of outputs, a more compact test solution also exists. The CT440 has the same wavelength accuracy and spectral coverage as the CTP10 and can perform IL/PDL measurements.
Photonic integrated circuits (PIC) are the technology currently deployed to tackle the bandwidth stress taking place in the transceiver industry. This stress is due to ever-increasing performance demands and costs pressures experienced by data centers and 5G applications.
End-to-end transceiver qualification requires an entire range of high-end optical and electrical testers. To help transceiver vendors ensure compliance throughout the transceiver lifecycle, EXFO offers a range of electrical and optical testing solutions from wafer-level to packaged devices, including the EA-4000 sampling scope and the BA-4000 bit error rate tester.
Design and manufacturing of PIC dies is maturing fast, with photonic wafers now containing thousands of components made available by foundries through process design kits (PDKs). To create and update these PDKs, wafer manufacturers require reliable testing solutions to optimize the different parameters of interest for a given optical component. Ring resonators have attracted a lot of attention in recent years and are commonly found in PIC designs to create extremely narrow peaks/troughs that can be used as modulators, for instance.
Testing is a crucial step after design and manufacturing to provide feedback to the design tools and help optimize them. It is also needed for process control, to ensure that devices operate as expected throughout the assembly and packaging of the PIC chips. The PIC devices are usually tested at the wafer level prior to dicing so as to detect defects as early as possible and to avoid packaging defective dies.
Using a PIC wafer probe station, light can be coupled in and out of each chip using specially designed optical fiber hardware and high-precision alignment software. It is also possible to couple several components simultaneously using a fiber array. Precision alignment and speed allow coupling optimization within a fraction of a second.
Once the light is coupled into the wafer, the optical characteristics of the DUT can be measured as a function of wavelength. Testing photonic devices is at the heart of EXFO’s expertise, and the CTP10 has been specifically developed to address the key PIC measurement challenges. The CTP10 can measure optical components with large spectral contrast in a single scan, reliably and accurately.
As in most cases with new technologies, it takes several areas of expertise to build a comprehensive solution.
That is why EXFO has combined forces with Hewlett Packard Enterprise (HPE) and MPI Corporation to jointly address the challenges posed by optical component testing through advanced, interoperable measurement techniques. Since they can easily be automated, EXFO’s instruments fit many wafer-level test solutions.
EXFO has also demonstrated interoperability with AEPONYX, a components manufacturer, and Maple Leaf Photonics, an integrated electro-photonics probe system developer, for PIC testing. The custom solution that was designed sets the stage for future advances in PIC design and testing. A 10-fold test speed increase was achieved as compared to previous technologies. Read the full story.
Unrivaled passive optical component testing platform for WDM components and photonic integrated circuits. The CTP10 yields fast, accurate and reliable results, under any test conditions for R&D and manufacturing environments. This powerful integrated test solution interfaces easily with many probe stations.
Improve production yield with R&D-grade solutions that rapidly provide best-in-class measurements. Active components (e.g., lasers inside transceivers, semi-conductor optical amplifiers) can be characterized within seconds by OSA20.
Passive optical components can be tested by CTP10 to picometer resolutions even under stringent conditions.
Flexibility is key in the race to 5G. Designed with the future in mind by collaborating with research groups, these solutions can be integrated into any wafer-testing handling system, with alignment included. CTP10 is an evolutive modular platform, allowing additional or new functions to be added to the system over time.
CTP10 fits into a single mainframe, ready to test components at the push of a button.
OSA20 and CTP10 come already packed with analysis features and special test configurations for easy setup.
User-friendly GUIs without any compromise on performance.
A full suite of SCPI automation commands allows the user to fully control the test gear and integrate it in a research test setup or production test bench.