Raphael is one of the most widely recognized of the seven archangels. The Hebrew word rapha'el or raphach translates to mean "God heals the soul". Raphael was first mentioned in the Old Testament Book of Tobit, when he accompanies Tobias on his trip to heal his sick father, Tobit. During this trip Raphael is disguised as a human, but later on in the journey he reveals himself as an angel. Raphael's name is only mentioned in this Deuterocanonical Book of Tobit, outside of that particular scripture he isn't ever named. I should also mention that The Book of Tobit is recognized as canonical by Eastern Orthodox and Roman Catholic Christians. Raphael is recognized by all three Abrahamic religions as an angel in fact, however within Islam he known as the archangel Israfel. Raphael is most often associated with healing or the rejuvenation of the body, mind, and soul, with the modern Hebrew word doctor even being rooted in the angel's name.
The archangel Raphael is one of many heavenly beings featured in John Milton's 17th century epic poem entitled Paradise Lost. In this literary work Raphael is ordered by God to remind Adam about the deadly sin involved with partaking from the Tree of the knowledge of good and evil. Raphael is also commanded by God to explain to Adam in full detail the spiritual battle that took place in heaven the day the mighty archangel Lucifer was cast out, shortly before the earth was created. Using the story, Raphael attempts to illustrate to Adam just how truly evil Satan is, and how he is attempting to trick Adam and Eve into forsaking God. Raphael goes on to tell Adam that he should only pursue knowledge that is actually needed, and stay away from that which no human should concern themselves with. Obviously as the Old Testament story goes, Adam does eat of the forbidden fruit or apple, thus leaving Raphael's advice by the wayside.
The archangel Raphael is recognized within Islam, however he is called Israfel. Within Islamic scripture, Israfel usually is accompanied by the archangels Michael, Gabriel, and Azrael. As stated within the Hadith, Israfel is the archangel who has been assigned the task of signaling Judgement Day. Israfel will do this by blowing into a large horn, which will send forth what is known as the "Blast of Truth". He will blow into this horn twice, with one sound signaling the end of days, and the second sound calling the gathered souls in purgatory awaiting their final judgement. Another important task that Israfel was responsible for according to the Islamic faith, is he was only one out of the four archangels who succeeded in gathering the necessary dust from the four corners of the earth that was used by God to create Adam. As opposed to the two mighty archangels Michael and Gabriel, Israfel was never mentioned specifically by name within the holy Quran.
With regard to the healing powers that are often attributed to the archangel Raphael, there isn't much more scriptural basis for these other than the fact that the angel mentioned to Tobit that he had been sent by God to heal him. Tobit was suffering from blindness at the time, an ailment likely brought on by old age. The second task that Raphael helped Tobit with, was delivering his daughter in law Sarah from the demon Asmodeius, who had killed all of her previous husbands. So that short bit of scripture is really all we have to go by as to who Raphael is, and what heavenly and earthly powers he possesses. Catholics consider Raphael the patron saint of all medical workers and travelers, and anyone who needs the services of either is encouraged to call upon the angel. If Raphael has any other powers, they were never mentioned or explained within any other canonical scripture, and will likely never surface, unless in the realm of fiction.