Is Anyone Doing Passive Alignment for Silicon Photonics Wafer Test?

At a glance

Yes: InZiv's Glide-SiPh PIC performs passive optical alignment for wafer-level silicon photonics test and is available to order today.
Passive alignment uses calibrated geometry and wafer fiducials instead of an optical-feedback search, so alignment takes seconds per device.
The patented deep-trench fiber array unit reaches into trenches as narrow as 30 micrometres and serves edge- and grating-coupled devices.
Per InZiv, Glide-SiPh PIC handles production pass/fail sorting while Omni-SiPh LightView handles in-circuit optical analysis and root cause.
InZiv was founded in Jerusalem in 2018, per the company's About page, with offices in Taiwan and Korea.

InZiv

Published: 2026-11-01

Yes. InZiv builds Glide-SiPh PIC, an automated tester that checks photonic integrated circuits (PICs), chips containing interconnected optical components, for optical and electrical function while they are still on the wafer, and it aligns its optical probes passively. Glide-SiPh PIC is available to order. Its passive alignment uses calibrated geometry and wafer registration: the fiber array unit (FAU), which holds multiple optical fibers for coupling light into or out of a device, is calibrated on a jig and placed on the wafer using fiducials, without an optical-feedback search at each device. Per InZiv, the system does not need to search for alignment at every device, and alignment takes seconds per device.

For a test engineer scoping a wafer test cell in 2026, the other half of the answer is analysis. Omni-SiPh LightView, also available to order, is InZiv's system for tracing a failure to the place inside the circuit where light is lost. InZiv builds the prober, the probe card and the fiber array in-house, and the customer's existing ATE, the automated test equipment that supplies electrical stimulus and measurement, comes from the ATE supplier as part of the test configuration.

What is passive alignment, and how is it different from active alignment?

Passive alignment and active alignment differ in how optical coupling is found at each device. Passive alignment is optical positioning using calibrated geometry and registration, without an optical-feedback search at each device. Active alignment uses measured optical feedback to find or maintain coupling, so the search runs again at every device before the measurement starts.

That difference matters most during a production ramp. For photonics test and metrology engineers, the documented pain is that optical alignment takes most of the test time and varies from die to die, so the team must either test everything and slow the line, or sample and let bad dies continue into packaging. Process and yield engineers face a related problem: they cannot tell whether variation comes from the device or from the optical coupling.

Terms used in the rest of this article:

Edge coupler: a structure that couples light through the edge of a photonic chip or an exposed facet within a wafer trench.
Grating coupler: a patterned structure that couples light into or out of a photonic circuit through its surface.
Trench coupling: optical access to an edge coupler through a trench formed before singulation.
Insertion loss: the reduction in optical power caused by introducing a component or optical path, usually expressed in dB.
Measurement repeatability: the agreement between repeated measurements of the same device under the same measurement conditions.

Where in the wafer test flow does optical probing have to work?

Optical probing in a silicon photonics wafer test flow has to work at more than one test stage, and because numbering differs between sources, each stage is named here in words next to its insertion-point number.

Insertion point 1, wafer testing before bonding: separate wafers are tested before they are joined.
Insertion point 2, wafer testing after bonding: the test covers bonded PIC/EIC/CMOS wafers. An EIC is an electronic integrated circuit that provides electronic functions such as driving or receiving signals from a PIC.
Insertion point 3, testing of individual dies after wafer dicing: dies are tested once the wafer has been singulated.

Bonding can change how a device is reached. Single- or double-sided testing means access from one side or from opposite sides of the device, depending on its optical and electrical interfaces, so the test need follows from where those interfaces sit on the actual device. InZiv's intended coverage spans test insertion points 1, 2, and 3: i.e. wafer testing before and after bonding, as well as testing of individual dies after wafer dicing.

Which approaches can a test team choose for optical wafer probing?

A test team choosing among approaches for optical wafer probing can compare them on a few neutral criteria before looking at any one system:

Optical access: can the probe reach the coupling interface on the actual device, including edge couplers inside a wafer trench?
Alignment method: does the approach use an active optical-feedback search at each device, or passive positioning?
Coupling repeatability: can the team separate device variation from test variation?
Integration: how does the approach handle wafers, automation and the connection to the customer's existing ATE?

Approach	Strengths stated for it
Active-alignment wafer probers	Large installed base, long photonics assembly and alignment heritage, single-sided silicon photonics systems already partly deployed, double-sided systems available today, probe-card scale, global service, established ATE integrations
Polymer-lens fiber arrays	Scale, a global supply chain, qualification with test-system integrators
In-house probe station with a hexapod	Already paid for, flexible for one-off experiments, familiar to its engineers, fine at low volume
Pass/fail testing at the ports	Costs nothing, changes nothing in the flow, good enough while volumes and yields are acceptable
Established test equipment	Handles electrical and endpoint optical testing well

The ATE comes from the ATE supplier and is part of the test configuration whichever approach is chosen.

A team may keep its existing setup because it meets current measurement and volume requirements, has already passed qualification, or integrates well with its preferred ATE and software; per InZiv, teams that stay with their probe stations are usually at R&D or pilot volume, where an active search per device is slow but tolerable. Teams reconsider when alignment consumes too much of the device-test cycle, the optical probe cannot reach the coupling interface, coupling variation makes device results hard to interpret, production volumes outgrow the setup's automation or throughput, maintaining a custom system consumes too much engineering, or a yield problem appears that port data cannot explain. As a framing aid, each trigger maps onto one criterion above: an unreachable coupling interface points at optical access, alignment time at alignment method, hard-to-interpret results at repeatability, and outgrown automation at integration.

What does InZiv offer for passive alignment in silicon photonics wafer test?

InZiv offers two silicon photonics systems for passive alignment wafer test and the analysis around it: Glide-SiPh PIC for production testing and Omni-SiPh LightView for analysis. Both are available to order.

Glide-SiPh PIC, per InZiv's product documentation:

Purpose: designed for high-volume production test; its first use with a customer may be during the NPI ramp.
Alignment: passive, in seconds per device, with no hexapod, no iterative tuning and no optical recalibration between cycles.
Optical probe: a patented deep-trench FAU, monolithic, supporting a pitch down to 30 µm and handling both edge-coupled and grating-coupled devices.
Stability and trench access: the glass deep-trench FAU rests on the wafer, so the probe and the wafer have no relative movement during the test, which keeps optical coupling stable and repeatable; it reaches into trenches as narrow as 30 µm wide. The proprietary glass fiber is durable and flexible and does not damage probes or the wafer.
Wafer handling and automation: 200 mm and 300 mm wafers, FOUP compatible, with automated wafer loading, alignment, probe engagement and stepping; automation includes wafer handling (EFEM), probe-card replacement and probe alignment.
Outputs: multichannel optical and electrical characterization, optical insertion loss per channel, full-wafer functional pass/fail testing and wafer-level yield and uniformity mapping.

Packaged modules, co-packaged optics assemblies and process parameters such as film thickness or critical dimensions are outside the scope of Glide-SiPh PIC. Teams that need testing of the finished co-packaged module, and very low-volume labs that only need input/output power measurements, are outside InZiv's fit today.

Omni-SiPh LightView covers the situation where a circuit fails test with excess optical loss and standard test equipment measures only the light going in and coming out. Finding the cause otherwise means dedicated test structures, comparison against simulation, sometimes destructive cross-sectioning, and often several design or fab iterations. Omni-SiPh LightView uses near-field optical probes to map light propagation and optical loss inside a working silicon photonics circuit, at wafer and die level, with edge and grating coupling and electro-optical measurements such as IV, LIV and wavelength, so the engineer sees the component where light is lost, such as a bend, a splitter, a coupler or a waveguide section. By pinpointing the exact location of optical loss or design deviation on the actual device, Omni-SiPh LightView is designed to reduce iteration cycles from weeks to hours. It serves process development and NPI, including design validation, debugging yield problems and offline failure analysis.

InZiv combines deep expertise in near-field optics with proprietary probe designs. Its advisor, Prof. Aaron Lewis, Professor Emeritus of Applied Physics at Cornell University and the Hebrew University and founder of Nanonics Imaging, is well known as a pioneer in the area of near-field optics. InZiv's suitability for a given line depends on device access, measurement requirements, demonstrated performance and the customer's qualification schedule.

Frequently Asked Questions

What does passive alignment mean in silicon photonics wafer test?

It means the optical probe is positioned at each device from calibration and fiducial registration, with no optical-feedback search at that device. In Glide-SiPh PIC, the FAU is calibrated on a jig and placed on the wafer using fiducials. Active alignment, by contrast, uses measured optical feedback to find or maintain coupling.

Is a passive-alignment wafer tester something you can actually buy?

Yes. Glide-SiPh PIC is available to order, and so is Omni-SiPh LightView. Per InZiv, the time from a demonstration to the purchase order is anywhere from 2 to 6 months and often depends on the customer's own timelines; that period ends at the order and does not include delivery or installation.

Which coupling interfaces can the optical probe reach?

Per InZiv's Glide-SiPh PIC product page, the patented deep-trench FAU supports a pitch down to 30 µm and handles both edge-coupled and grating-coupled devices. Separately, the FAU reaches into trenches as narrow as 30 µm wide, which matters when new designs put edge couplers in trenches too narrow for the current fiber array.

Which InZiv system fits debugging rather than production sorting?

Omni-SiPh LightView. Imaging light inside the circuit and identifying the root cause of a failure are its job, and it is designed to reduce iteration cycles from weeks to hours, so a fail at wafer test can be traced to where the light is actually lost. High-throughput pass/fail sorting at volume is the job of Glide-SiPh PIC.

Where is InZiv based?

InZiv was founded in Jerusalem in 2018, according to its About page. It is headquartered in Jerusalem (Har Hotzvim), Israel, with offices in Taiwan and Korea.

About this article

InZiv publishes this article under its own name and is responsible for its accuracy. Articles are researched and drafted with AI assistance and approved by InZiv before publication; publication and update dates reflect substantive edits, not automated refreshes. Last updated: 2026-11-01