# Fock State Preparation in a Gaussian Backend

**URL:** <https://discuss.pennylane.ai/t/fock-state-preparation-in-a-gaussian-backend/3383>\
**Category:** Strawberry Fields\
**Created:** [September 1, 2023, 9:31pm UTC](https://discuss.pennylane.ai/t/fock-state-preparation-in-a-gaussian-backend/3383 "2023-09-01T21:31:38Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Omar\_Ibna\_Nazim](https://yyz2.discourse-cdn.com/flex012/user_avatar/discuss.pennylane.ai/omar_ibna_nazim/32/1688_2.png) [@Omar\_Ibna\_Nazim](https://discuss.pennylane.ai/u/Omar_Ibna_Nazim)\
**Post date:** [September 1, 2023, 9:31pm UTC](https://discuss.pennylane.ai/t/fock-state-preparation-in-a-gaussian-backend/3383/1 "2023-09-01T21:31:38Z")

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Is it possible to prepare a Fock state in a gaussian backend and implement it in currently available real devices? For example, via photon number measurement?

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**Author:** ![isaacdevlugt](https://yyz2.discourse-cdn.com/flex012/user_avatar/discuss.pennylane.ai/isaacdevlugt/32/1159_2.png) [@isaacdevlugt](https://discuss.pennylane.ai/u/isaacdevlugt)\
**Post date:** [September 5, 2023, 4:25pm UTC](https://discuss.pennylane.ai/t/fock-state-preparation-in-a-gaussian-backend/3383/2 "2023-09-05T16:25:19Z")

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Hey @Omar_Ibna_Nazim!

Since the Fock basis is non-Gaussian, it can only be used with Fock backends, not the Gaussian backend.

Depending on your application, and since StrawberryFields is in maintenance mode (crucial bugs will be fixed, but no new features added), I recommend that you check out Mr Mustard: [Basic API Reference — Mr Mustard 0.5.0 documentation](https://mrmustard.readthedocs.io/en/stable/introduction/basic_reference.html)

It’s another photonic software offering from Xanadu that we’re active with 😁. Let me know if you have any questions about it!