Method for improving the polarization extinction ratio of multifunction integrated optic circuits.

The polarization extinction ratio (PER) of the multifunction integrated optic circuit (MIOC) is significant in maintaining polarization reciprocity in the fiber-optic gyroscope (FOG), and a high PER value is required, particularly in high-precision FOGs. Practically, the value of the PER decreases owing to the recoupling of the TM mode to the output port, thereby degrading the performance of the FOG. To improve the PER, the propagation of the leaking TM mode in the substrate is analyzed first.

p53-/- synergizes with enhanced NrasG12D signaling to transform megakaryocyte-erythroid progenitors in acute myeloid leukemia.

Somatic mutations in TP53 and NRAS are associated with transformation of human chronic myeloid diseases to acute myeloid leukemia (AML). Here, we report that concurrent RAS pathway and TP53 mutations are identified in a subset of AML patients and confer an inferior overall survival. To further investigate the genetic interaction between p53 loss and endogenous Nras in AML, we generated conditional Nrasp53 mice.

Structure optimization of small-diameter polarization-maintaining photonic crystal fiber for mini coil of spaceborne miniature fiber-optic gyroscope.

A small-diameter polarization-maintaining photonic crystal fiber (PM-PCF) for mini coils of spaceborne miniature fiber-optic gyroscopes is proposed in this paper. To ensure the strength of the small-diameter PM-PCF, a four-ring air holes structure is adopted. Using the full vector finite element method, dependence studies of modal field distribution, birefringence, and confinement loss on several key structure parameters are numerically investigated.

Phase sensitivity to temperature of the guiding mode in polarization-maintaining photonic crystal fiber.

The propagating phase changing of a polarization-maintaining photonic crystal fiber (PM-PCF) caused by temperature variation is theoretically studied, as well as compared with conventional PANDA fiber. As to verifying numerical analysis, a platform based on a Michelson interferometer for phase versus temperature measurement was built for both kinds of fiber. Experiments show that PM-PCF has similar temperature sensitivity with conventional polarization-maintaining fiber.

Analysis of sensing coil polarization properties' effect on performance of fiber optical gyroscope.

The mechanism of fiber coil polarization properties' effect on the performance of a fiber optical gyroscope (FOG) is investigated with analysis of secondary wave trains' polarization evolution and interference in the fiber coil. Based on the optical model, the simulation demonstrates that the bias error varies nonlinearly with the fiber coil polarization crosstalk, and the experiment verifies the analysis and simulation result, so some measures are promoted to reduce the bias' dependence on the fiber coil's polarization properties, which is significant for improving environmental adaptability and long-term stability of the FOG.