# Laser light delivery for a diagnostic test cartridge

Canonical: https://www.formlightoptics.com/portfolio/diagnostic-cartridge-laser-delivery
Markdown: https://www.formlightoptics.com/portfolio/diagnostic-cartridge-laser-delivery.md

Co-designed a cartridge lens and lightguide that put far more laser light onto a small detection zone.

Point-of-care diagnostics company. 2025.

Capabilities: Illumination, Lightguides, Simulation.

### Challenge

A laser diode had to excite a small sensing well inside a disposable cartridge. The existing lens delivered only about a quarter of the light into the detection area. Any change had to fit the cartridge's mechanical limits and work at both near and far cartridge positions.

### Approach

We modeled the baseline in non-sequential ray tracing, normalized to 1 W, to track efficiency and peak irradiance together. We then optimized the lens and a new lightguide as one system and iterated with the client's mechanical team on fit. Each candidate was checked at near and far positions and with the cartridge film in place.

### Result

The final lens and lightguide reached about 90% efficiency at both positions, with a large gain in peak irradiance on the target. That design was built.

### Key figures

- 25% to 90%: optical efficiency into the detection area
- ~30x: peak irradiance on target

Tools: TracePro.

Related services: [Illumination design](https://www.formlightoptics.com/services/illumination-design), [Stray light and non-sequential simulation](https://www.formlightoptics.com/services/stray-light-and-non-sequential-simulation).