An optical system and an SSD module that maintain optimal SI, PI and EMI characteristics without a shield based on a ground voltage and an impedance match. The optical system includes a solid state drive (SSD) module and an input/output (I/O) interface. The SSD module includes a plurality of solid state memory units. The input/output (I/O) interface receives data to be written to at least one of the solid state memory units from a main memory unit, the input/output (I/O) interface transmits data written in at least one of the solid state memory units to the main memory unit. The SSD module and the I/O interface transmit and receive data using an optical medium.