Embedded heterostructure epitaxy: A technique for two-dimensional thin-film definition

Selective multilayer epitaxial growth of GaAs-Ga1–xAlxAs through stripe openings in Al2O3 mask is reported. The technique results in prismatic layers of GaAs and Ga1–xAlxAs "embedded" in each other and leads to controllable uniform structures terminated by crystal faces. The crystal habit (shape) has features which are favorable for fabrication of cw injection lasers, laser arrays, and integrated optics components which require planar definition

Low-threshold room-temperature embedded heterostructure lasers

Room-temperature embedded double-heterostructure injection lasers have been fabricated using selective liquid phase epitaxial growth. Threshold current densities as low as 1.5 kA/cm^2 have been achieved in lasers grown through stripe windows opened in epitaxial GaAlAs masks

Room-temperature operation of GaAs Bragg-mirror lasers

Room-temperature operation of GaAs distributed Bragg reflector lasers is reported. The diodes are fabricated from conventional double heterostructures involving only a single step of liquid-phase epitaxy. For gratings with a period of 3700 Å, the diodes lased at 8770 Å, which corresponds to the high-absorption side of the spontaneous emission spectrum. Thresholds as low as 6 kA/cm^2 have been realized

bitcoin.BitMint: Reconciling Bitcoin with Central Banks

The sweeping success of the original (2008) bitcoin protocol proves that digital currency has arrived. The mounting opposition from the financial establishment indicates an overshoot. We propose to tame bitcoin into bitcoin.BitMint: keeping the bitcoin excitement -- fitted into real world security, stability and fraud concerns. The basic idea is to excise the bitcoin money generation formula, and otherwise apply bitcoin essentially “as is” over digital coins which are redeemable by the mint that minted them. This will preserve the bitcoin assured anonymity. The new bitcoin.BitMint solution will benefit from bitcoin’s double-spending prevention, and would otherwise enjoy all the benefits associated with money in a digital form. bitcoin.BitMint will allow traders to invest in US$, gold, or any other commodity while practicing their trade in cyberspace, anonymously, securely, and non-speculatively. This “mint-in-the-middle” protocol will allow law enforcement authorities to execute a proper court order to enforce the disclosure of a suspected fraudster, but the community of honest traders will trade with robust privacy as offered by the original bitcoin protocol. We envision interlinked bitcoin.BitMint trading environments, integrated via an InterMint protocol: a framework for the evolution of a cascaded super currency – global and highly stable