|Wa `alaykum As-Salamu wa Rahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
Dear brother in Islam, thanks a lot for your question which reflects your care to have a clear view of the teachings of Islam. Allah commands Muslims to refer to people of knowledge to get themselves well-acquainted with the teachings of Islam as well as all aspects of life.
In Islam, we are not allowed to tarnish the honor of anyone. One is required to produce four witnesses when making an allegation of adultery against another person; otherwise, one will be guilty of slandering.
A raped woman is a victim that must be treated with honor and kindness. She is not required to produce four witnesses to prove the crime done against her, nor is she punished for the crime done against her.
In his response to your question, Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states:
Excerpted, with slight modifications, from: www.muslims.ca
You can also read:
Allah Almighty knows best.