Several optical methods have been proposed for implementation of all optical logic and arithmetic devices during the last few decades. In this regard, the role of optical tree architecture can be mentioned as an important approach for conversion of an optical data from binary to decimal and vice-versa. In this communication, the authors propose a new concept of conversion of a binary number having fraction (fractional value) to its equivalent decimal counterpart to any desired number of places after decimal using a single optical circuit with outputs rearranged. In this operation, optical tree and some nonlinear material based switches are used properly owing to their high speed.