# Page Not Found The URL `kostacloud/optical-design/optical-design-modes/imaging/gradient-index-optics-grin` does not exist. This page may have been moved, renamed, or deleted. ## Suggested Pages You may be looking for one of the following: - [Gradient Index Optics (GRIN)](https://docs.kostacloud.com/kostacloud/advanced-optics-ray-trace/gradient-index-optics-grin.md) - [Gratings, Kinoforms, and Phase Masks](https://docs.kostacloud.com/kostacloud/advanced-optics-ray-trace/gratings-kinoforms-and-phase-masks.md) - [Light Pipe/Fiber](https://docs.kostacloud.com/kostacloud/3d-geometric-elements/light-pipe-fiber.md) - [Parameter (Optimization)](https://docs.kostacloud.com/kostacloud/parameter-optimization.md) - [Optical Materials](https://docs.kostacloud.com/kostacloud/material-library/optical-materials.md) ## How to find the correct page If the exact page cannot be found, you can still retrieve the information using the documentation query interface. ### Option 1 — Ask a question (recommended) Perform an HTTP GET request on the documentation index with the `ask` parameter: ``` GET https://docs.kostacloud.com/kostacloud/advanced-optics-ray-trace/gradient-index-optics-grin.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. ### Option 2 — Browse the documentation index Full index: https://docs.kostacloud.com/sitemap.md Use this to discover valid page paths or navigate the documentation structure. ### Option 3 — Retrieve the full documentation corpus Full export: https://docs.kostacloud.com/llms-full.txt Use this to access all content at once and perform your own parsing or retrieval. It will be more expensive. ## Tips for requesting documentation Prefer `.md` URLs for structured content, append `.md` to URLs (e.g., `/kostacloud/advanced-optics-ray-trace/gradient-index-optics-grin.md`). You may also use `Accept: text/markdown` header for content negotiation.