We present a design of balanced homodyne receivers suitable for ultra-low noise quantum applications such as continuous-variable key distribution and random number generation. For best bandwidth performance die-level low-parasitic photodiode together with low-noise high-speed transimpedance amplifier are explored planar lightwave circuit splitter chip serving photomixer. Bandwidths 750 MHz 2.6 ...

 Let $R$ be a ring‎, ‎and let $n‎, ‎d$ be non-negative integers‎. ‎A right $R$-module $M$ is called $(n‎, ‎d)$-projective if $Ext^{d+1}_R(M‎, ‎A)=0$ for every $n$-copresented right $R$-module $A$‎. ‎$R$ is called right $n$-cocoherent if every $n$-copresented right $R$-module is $(n+1)$-coprese-nted‎, ‎it is called a right co-$(n,d)$-ring if every right $R$-module is $(n‎, ‎d)$-projective‎. ‎$R$...

Experimental results are presented to show that SMA actuators are able to control forces both rapidly and precisely. An antagonistic pair of constrained actuators is shown to be capable of rapidly changing the setpoint throughout a 7.00 N range. Although the system entered into a limit cycle at the setpoint, the limit cycle magnitude was small. The peak to peak amplitude of the limit cycles was...