Abstract: An optical system affixed to an electronic apparatus is provided, including a first optical module, a second optical module, and a third optical module. The first optical module is configured to adjust the moving direction of a first light from a first moving direction to a second moving direction, wherein the first moving direction is not parallel to the second moving direction. The second optical module is configured to receive the first light moving in the second moving direction. The first light reaches the third optical module via the first optical module and the second optical module in sequence. The third optical module includes a first photoelectric converter configured to transform the first light into a first image signal.

Abstract: Provided is a method of making colloidal metal nanoparticles. The method includes the steps of: mixing a metal aqueous solution and a reducing agent to form a mixture solution in a reaction tank; heating the mixture solution and undergoing a reduction reaction to produce a composition containing metal nanoparticles, residues and gas, wherein the amount of the residues is less than 20% by volume of the mixture solution, and guiding the gas out of the reaction tank; dispersing the metal nanoparticles with a medium to obtain colloidal metal nanoparticles. By separating the reduction reaction step and the dispersion step, the method of making colloidal metal nanoparticles is simple, safe, time-effective, cost-effective, and has the advantage of high yield.

Abstract: A method of making the inorganic gold compound, such as tetrachloroauric acid, sodium tetrachloroaurate, potassium tetrachloroaurate, sodium tetracyanoaurate, and potassium tetracyanoaurate, includes the step of: treating gold with a halogen-containing oxidizing agent in a hydrochloric acid to obtain the inorganic gold compound, wherein the halogen-containing oxidizing agent excludes chlorine gas. The method of making the inorganic gold compound is simple, safe, time-effective, cost-effective, and environment-friendly, and has the advantage of high yield.

Abstract: A method of making the inorganic gold compound, such as tetrachloroauric acid, sodium tetrachloroaurate, potassium tetrachloroaurate, sodium tetracyanoaurate, and potassium tetracyanoaurate, includes the step of: treating gold with a halogen-containing oxidizing agent in a hydrochloric acid to obtain the inorganic gold compound, wherein the halogen-containing oxidizing agent excludes chlorine gas. The method of making the inorganic gold compound is simple, safe, time-effective, cost-effective, and environment-friendly, and has the advantage of high yield.