Are optical quantum information processing experiments possible without beamsplitter?

The significance of beamsplitter in experimental optical quantum information processing and quantum technology is discussed with a focus on the role of a beamsplitter-type Hamiltonian in the recent development in this field of research. Here, we follow a new approach to briefly describe quantum measurement, Bell measurement, quantum state engineering, quantum teleportation, cryptography, and computation using both discrete and continuous variables to establish the wide applications of beamsplitter-type operation. Finally, we also discuss the limitations of this linear optical element.