In this research an approach to all optical delta sigma modulator (ADSM) has been elaborated. Two important components of ADSM; "leaky integrator" and "inverted bi-stable quantizer" were modeled, on the basis of cross gain modulation of the Semiconductor Optical Amplifier (SOA). The simulations (via VPI photonics) were all in micrometer scale (suitable for chip fabrication). By simulating each element of ADSM the whole circuit was simulated and results have been showed and analyzed. By investigating the ADSM, the limiting factor for reaching higher frequencies (THz) was recognized to be the quantization device. Thus a new optical switch was introduced, for the first time so called "proteresis." By applying proteretic bi-stable device in the delta sigma modulator, the resonance frequency was improved minimum two fold from 295MHz to 575MHz without making any change in hysteretic bi-stable switch. The broad impact of this research is on the digital technologies that can be utilized in high-speed signal processing. The prime examples are the RF technologies used in military and civilian applications. Furthermore introduction of proteresis opens a new research gate for compensating delay in almost every system.

In this research an approach to design and implement all-optical delta-sigma modulator (ODSM) has been expanded. The two main blocks of this modulator are “leaky integrator” and “bi-stable switch” designed and implemented by using active element like semiconductor optical amplifier (SOA) and other passive elements like optical filter, isolator and coupler. All experiments are done on optical table and proper results achieved. Thus the new bi-stable switch is designed and implemented by using “inverted bistable switch” and “non-inverted bi-stable switch”. This switch is made by five ring lasers. Right wavelengths have chosen for each ring laser to achieve a novel characteristic called “Proteresis”. All control parameters of this switch was investigated The major impact of this research will be in the area communication system, which need high resolution and fast modulation speed with less noise in their systems.