Final answer:
Muslims did not significantly contribute to forced religious conversions, as the Islamic Empire allowed non-Muslims to practice their religions within a certain framework that recognized both their rights and Islamic sovereignty.
Step-by-step explanation:
The question asks about areas where Muslim contributions did not extend. During post-conquest periods, Muslims were known for their advancements in various fields such as trade, mathematics, science, and law, a testament to their influence spanning from Spain to the Indus River valley. The description of the early Islamic community underlines the tolerant approach towards non-Muslims and the importance of trade, learning, and the exchange of ideas under the Islamic Empire. Nonetheless, the conquests and spread of Islam did not necessarily enforce religious conversion, hence Islamic rule did not significantly contribute to forced religious conversions as non-Muslims were allowed to continue their practices within a framework, like the dhimmi system and millet system, which recognized religious diversity while establishing Islamic sovereignty.