Silicon quantum dot laser

DETAILED DESCRIPTION An object of the present invention is to provide apparatus and methods to dynamically vary or control the color of light emitted by a silicon quantum dot laser.
Such capability provides greater utility for the laser, for example as a pixel in a color display for moving images.
In order to accomplish this object, a plurality of first-sized quantum dots is provided to produce a first color of light, a plurality of second-sized quantum dots produce a second color of light, and a plurality of third-sized quantum dots produce a third color of light.
Means for causing the first-sized dots, the second-sized dots, and the third-sized dots to produce varying amounts of light allows a variety of colors to be perceived by the human eye.
The device emits light perpendicular to its surface.
The light is resonated in order to make it coherent.
Apparatus in accordance with this invention produces dynamically varying colors of light employing a plurality of first-sized quantum dots for producing a first color of light which are selectively caused by a first controller to produce a varying amount of light.
A plurality of second-sized quantum dots are arranged for producing a second color of light in varying amounts as selected by a second controller.
Yet another plurality of third-sized quantum dots produces a third color of light in varying amounts as selected by a third controller.
At least a portion of the first and second colors of light or of the first, second, and third colors of light: is then extracted from the apparatus.
This apparatus can include an arrangement for resonating the produced light for stimulating coherent light emission.
The extracted light is that which is normal to a surface of the apparatus.
The light extraction is performed in one embodiment by sectors of concentric circular grating, the spacing of said grating sectors being a function of the light extracted.
Preferably the grating sector spacing is proportional to the wavelength of the light extracted.
The controllers can stimulate the associated quantum dots via contacts for selectively voltage biasing those quantum dots