Ultrathin Film Lasing

A laser comprising:

• a power source effective to produce light;
• a substrate in communication with the power source, where the substrate includes a film, the film includes nanoparticles, wherein the length, width, and height of the nanoparticles are below 100 nm, the nanoparticles in the film are coupled nanoparticles, wherein the coupled nanoparticles are in disordered contact with each other within the film, and a distribution of the coupled nanoparticles on the substrate is effective to produce constructive interference of the light by multiple scattering at the boundaries of the coupled nanoparticles within the film.

A sensing device comprising:

• a substrate;
• a film on the substrate, wherein the film includes nanoparticles, the length, width, and height of the nanoparticles are below 100 nm, the nanoparticles in the film are coupled nanoparticles the coupled nanoparticles are in disordered contact with each other within the film, and a distribution of the coupled nanoparticles on the substrate is effective to produce constructive interference of a first light by multiple scattering at boundaries of the coupled nanoparticles within the film;
• a sensing element in optical communication with the film, wherein the film is effective to receive the first light and emit second light and a quantity of lumens of the second light is greater than a quantity of lumens of the first light, the sensing element is effective to detect the second light and generate a response.