We experimentally demonstrate a polarization-entangled photon source at 810 nm using type-II phase-matched periodically poled potassium titanyl phosphate (PPKTP) crystal pumped by low-cost, broadband laser diode with central wavelength of 405 and typical bandwidth 0.53 nm. The PPKTP is placed in Sagnac loop to realize the compact size high stability. downconverted biphotons, signal idler, have ...

Recently, considerable attention has been placed upon exploiting the negative-feedback effect in accelerating the quenching time of the avalanche current in passively quenched single-photon avalanche-diode (SPAD) circuits. Reducing the quenching time results in a reduction in the total charge generated in the SPAD, thereby reducing the number of trapped carries; this, in turn, can lead to impro...

The dose measurements of the small field sizes, such as conical collimators used in stereotactic radiosurgery (SRS), are a significant challenge due to many factors including source occlusion, detector size limitation, and lack of lateral electronic equilibrium. One useful tool in dealing with the small field effect is Monte Carlo (MC) simulation. In this study, we report a comparison of Monte ...

Introduction: Craniospinal radiotherapy is a therapeutic technique for central nervous system (CNS) tumors, which requires meticulous attention to technique and dosimetry.Treatment planning system (TPS) is one of the main equipment in radiotherapy; therefore, the evaluation of its accuracy is essential for dose calculation. The present study evaluates the validity of Isogray TPS in craniospinal...

The effects of injection locking a laser diode which is also subject to varying levels of optical feedback from an external Ž . reflector are investigated. It is found that the locking range of a laser diode with optical feedback LDWOF is reduced relative to that of a solitary laser diode depending on both the increased photon lifetime and the amount of optical feedback. When the LDWOF is locke...