A 197.2THz (1520.2nm) ITU-T grid distributed feedback (DFB) diode laser is frequency stabilized at 197.198THz by 1ocking its second harmonic (SH) signal on the rubidium 5S1/27S1/2 two-photon transition at 394.396THz (760.1 nm). With 100mW from the DFB diode laser and amplifying by an erbium-doped fiber amplifier, we obtain an SH power of 15mW using a periodically poled lithium niobate (PPLN) wa...

We demonstrate a compact solid-state laser source for high-resolution two-photon spectroscopy of the 1S-2S transition in atomic hydrogen. The source emits up to 20 mW at 243 nm and consists of a 972 nm diode laser, a tapered amplifier, and two doubling stages. The diode laser is actively stabilized to a high-finesse cavity. We compare the new source to the stable 486 nm dye laser used in previo...

We report on a low-noise diode laser oscillator at 972 nm actively stabilized to an ultrastable vibrationally and thermally compensated reference cavity. To increase the fraction of laser power in the carrier we designed a 20 cm long external cavity diode laser with an intracavity electro-optical modulator. The fractional power in the carrier reaches 99.9%, which corresponds to an rms phase noi...

objective: using megavoltage photons generated by medical linear accelerator is a common modality for the treatment of malignant. the crucial problem for using photon beams >8mv is the photoneutron yields that increase the risk of secondary cancer that treated with high-energy photon beams. the contaminated neutrons produced in different components of the accelerator head and rely on many param...

background: estimating dosimetric parameters for small fields under non-reference conditions leads to significant errors if done based on conventional protocols used for large fields in reference conditions. hence, further correction factors have been introduced to take into account the influence of spectral quality changes when various detectors are used in non-reference conditions at differen...

Background: Monte Carlo method (MC) has played an important role in design and optimization of medical linacs head and beam modeling. The purpose of this study was to compare photon beam features of two commercial linacs, Varian 21EX and Elekta SL-25 using MCNP4C MC code. Materials and Methods: The 6MV photon beams of Varian 21EX and Elekta Sl-25 linacs were simulated based on manufacturers pro...

Abstract Propagation of light by Anderson localization has been demonstrated in micro-nano-structured fibers. In this work, we introduce a phase separated glass optical fiber for quantum applications. By using spontaneous parametric down-conversion source, multi-photon detection with single-photon avalanche diode array camera, and signal post-processing techniques, demonstrate transport, where ...

On-chip ESD protection circuits realized with novel diode structures without the field-oxide boundary across the p/n junction are proposed. A PMOS (NMOS) is especially inserted into the diode structure to form the PMOS-bounded (NMOS-bounded) diode, which is used to block the field oxide isolation across the p/n junction in the diode structure. Without the field oxide boundary across the p/n jun...