At a glance
- Near-field optical probing measures light behavior inside a working photonic integrated circuit without cutting it, so geometry-only cross-sections stop being the fallback.
- Omni-SiPh LightView maps light propagation and optical loss inside silicon photonics circuits at wafer and die level, without damaging the device.
- Port measurements report total insertion loss only; in-circuit optical characterization shows which bend, splitter, coupler or waveguide section loses the light.
- Omni-SiPh LightView is designed to reduce iteration cycles from weeks to hours by locating loss on the actual device.
- Omni-SiPh LightView serves process development, design validation and failure analysis; Glide-SiPh PIC handles high-volume production pass/fail testing.
InZiv
Published:
To see how light behaves inside a photonic integrated circuit (PIC), a chip containing interconnected optical components, without sectioning it, the tool class to evaluate is near-field optical probing. Near-field optics means optical measurement at very short distances, including access to the evanescent field, an optical field that extends beyond a guiding structure and decays rapidly with distance. InZiv's 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. Engineers see where light is lost and why, without damaging the device, and as of 2026 Omni-SiPh LightView is available to order.
Cross-sectioning disappoints for a structural reason: a destructive cross-section shows the geometry and nothing about how the light behaved. Standard test equipment sits at the other extreme, measuring only the light going in and coming out. Omni-SiPh LightView is designed to reduce iteration cycles from weeks to hours by pinpointing the exact location of optical loss or design deviation on the actual device.
Which tools measure light behavior directly inside a photonic integrated circuit?
The tools that measure light behavior inside a photonic integrated circuit differ mainly by where along the optical path they observe the signal. Two categories matter for non-destructive measurement on a working device.
Port-level optical test. Light is coupled in at an input facet or grating coupler and collected at the output, giving insertion loss, the reduction in optical power caused by introducing a component or optical path, usually expressed in dB. Pass/fail testing at the ports costs nothing, changes nothing in the existing flow and is good enough while volumes and yields are acceptable. It reports how much light was lost, without saying where.
Near-field optical probing. A probe works close enough to the circuit to access its evanescent field, which lets the engineer observe positions between the ports. Omni-SiPh LightView belongs to this category.
Attributes worth specifying when you evaluate any in-circuit optical tool:
- Observation point: ports only, or positions inside the circuit.
- Device state during measurement: working and intact, or sectioned.
- Sample format: wafer level, die level, or both.
- Coupling supported: edge couplers, grating couplers, or both.
- Probe access: whether the probe can reach the structures you need to measure in your design.
What does non-destructive in-circuit optical measurement actually mean?
Non-destructive in-circuit optical measurement means spatially resolved optical measurement within an accessible photonic circuit, taken on the working circuit instead of a sectioned die. The word "inside" is used in two ways in photonics test.
Port-level electro-optical characterization. This combines the device's optical and electrical response, such as insertion loss, wavelength response and IV, measured at the ports. A directional coupler whose measured split ratio is off and shifts with wavelength shows the deviation at the ports, while the coupling region itself stays a black box.
Spatially resolved in-circuit mapping. A near-field probe interacts with the evanescent field of the circuit, so the engineer sees the component where light is lost, such as a bend, a splitter, a coupler or a waveguide section.
This article uses in-circuit optical measurement in the spatially resolved sense. Two more terms:
- Destructive cross-sectioning: physically sectioning a die to expose its geometry. The device does not survive it.
- Propagation loss: optical power loss per unit distance as light travels through a waveguide, commonly expressed in dB/cm.
Why does destructive cross-sectioning still happen, and what does it cost a program?
Destructive cross-sectioning still happens when a taped-out device returns with excess loss, because port-level measurements cannot localize the loss. For a device whose measured split ratio is off and shifts with wavelength while the simulation says the design is correct and the process data says the wafer is within spec, the geometry a cross-section reveals leaves the question open.
In InZiv's typical scenario, a PIC that fails test with excess optical loss sends engineers through some combination of these routes to the cause:
- dedicated test structures;
- comparison against simulation;
- sometimes destructive cross-sectioning, which consumes the device;
- often several design or fab iterations, where another tape-out costs months.
With Omni-SiPh LightView, root cause comes from one measurement on the actual device.
How do the available measurement approaches compare on what they reveal?
The available measurement approaches compare most usefully on what each reveals about the light inside the circuit. The table below uses only what InZiv's framing and typical scenario state for each approach.
| Approach | What InZiv's framing states for it |
|---|---|
| Pass/fail testing at the ports | Costs nothing, changes nothing in the flow and is good enough while volumes and yields are acceptable |
| Standard test equipment | Handles electrical and endpoint optical testing well; measures only the light going in and coming out |
| Dedicated test structures and comparison against simulation | Routes to the cause of excess optical loss in InZiv's typical scenario |
| Destructive cross-sectioning | Shows the geometry and nothing about how the light behaved |
| Another tape-out | Costs months |
| Omni-SiPh LightView (near-field optical probing) | Shows the component where light is lost inside the working circuit, at wafer or die level |
Omni-SiPh LightView is the near-field approach in this set. It serves process development and new product introduction (NPI), including design validation, debugging yield problems and offline failure analysis when something goes wrong in production.
How does Omni-SiPh LightView support in-circuit electro-optical measurement?
Omni-SiPh LightView supports in-circuit electro-optical measurement by bringing near-field optical probes to the working circuit and pairing the optical map with electro-optical measurements. Its role is analysis: imaging light inside the circuit and identifying the root cause of a failure.
| Attribute | What InZiv states |
|---|---|
| Measurement principle | Near-field optical probes map light propagation and optical loss inside a working silicon photonics circuit |
| Measurement scale | Wafer level and die level |
| Coupling supported | Edge coupling and grating coupling |
| Electro-optical data | IV, LIV and wavelength |
| Probe options | Near-field, deep-trench and angled probes, plus custom probe designs for specific customer architectures |
| Device condition | Engineers see where light is lost and why, without damaging the device |
| Availability | Available to order |
On iteration time, Omni-SiPh LightView 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.
Frequently Asked Questions
Which InZiv system covers production test and which covers analysis?
InZiv builds Glide-SiPh PIC for production testing and Omni-SiPh LightView for analysis. High-throughput pass/fail sorting at volume is the job of Glide-SiPh PIC, while root-cause work inside the circuit belongs to Omni-SiPh LightView. Packaged modules, co-packaged optics assemblies and process parameters such as film thickness or critical dimensions sit outside the scope of Glide-SiPh PIC. Both systems are available to order.
How long does an equipment evaluation usually run?
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, and that period ends at the order, without delivery or installation. A purchase typically runs from a technical discussion and a review of the device architecture and test requirements, through sample-based demonstration or feasibility work and agreement on configuration and acceptance criteria, to a commercial proposal, the order, and installation and acceptance. A pilot or on-site evaluation may be included and is optional.
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