TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The semi-polar crystal plane: is a (30-31), (30-3-1), (40-41) or (40-4-1) plane; and is a top surface of a vicinal, miscut, or off-axis free standing gallium nitride substrate (302). The III-nitride layers comprises at least one indium gallium nitride layer having a thickness greater than or equal to a Matthews-Blakeslee critical thickness, where the critical thickness is for an indium gallium nitride layer deposited on a semi-polar crystal plane of gallium nitride oriented greater than or equal to 15 degrees from the m-plane and in the c-direction of the gallium nitride. The III-nitride layers further include a light emitting indium gallium nitride active layer including at least one indium gallium nitride quantum wells, where the quantum wells have an indium composition of at least 16%, preferably 7% and a thickness of greater than 4 nm. The optoelectronic device is a laser diode and the indium gallium nitride layer comprises an indium gallium nitride waveguide that provides a modal confinement for the laser diode, where the laser diode has a lasing peak at a wavelength of at least 460 nm. The optoelectronic device is grown on a miscut or vicinal surface of the gallium nitride substrate, where the miscut or vicinal surface includes the semi-polar crystal plane, and the III-nitride layers further comprise: at least one n-type (aluminum-indium-gallium)nitride layer; at least one p-type (aluminum-indium-gallium)nitride layer; and an indium gallium nitride active layer comprising at least one indium gallium nitride quantum well layer between the n-type and the p-type (aluminum-indium-gallium)nitride layers, where the n-type (aluminum-indium-gallium)nitride layer, p-type (aluminum-indium-gallium)nitride layer, and the indium gallium nitride quantum well layers have a semi-polar orientation of the semi-polar crystal plane and the indium gallium nitride quantum well layers have a peak light emission or a peak light absorption at a wavelength of at least 477 nm. In the optoelectronic device, the III-nitride layers comprise: an n-type gallium nitride layer (308) on or above the semi-polar crystal plane; an n-type indium gallium nitride waveguiding layer (310) on or above the n-type gallium nitride layer, where the n-type indium gallium nitride waveguiding layer has a thickness of at least 50 nm and an indium composition of greater than or equal to 7%; an indium gallium nitride active layer on or above the n-type indium gallium nitride waveguiding layer, including indium gallium nitride quantum well layers with an indium composition of at least 7% and a thickness of more than 4 nm; a p-type indium gallium nitride waveguiding layer (318) on or above the indium gallium nitride active layer; and a p-type gallium nitride layer (320) on or above the p-type indium gallium nitride waveguiding layer having a thickness of at least 50 nm and an indium composition of greater than or equal to 7%, where the III-nitride layers have a semi-polar orientation of the semi-polar crystal plane. The semi-polar crystal plane comprises anatomically specific plane, so that a smooth epitaxial growth of the III-nitride layers is achieved. The device is a laser diode grown on the semi-polar crystal plane, where the laser diode comprises a waveguide oriented in a c-projection direction of the laser diode, for higher gain. Preferred Method: In the method, the depositing step comprises depositing the indium gallium nitride layer. The depositing step further includes: depositing the light emitting indium gallium nitride active layer; depositing the n-type (aluminum-indium-gallium)nitride layer on the semi-polar crystal plane, depositing indium gallium nitride active layer comprising the indium gallium nitride quantum well layer on or above the n-type (aluminum-indium-gallium)nitride layer, and depositing p-type (aluminum-indium-gallium)nitride layers on the indium gallium nitride quantum well layers; depositing the n-type gallium nitride layer on or above the semi-polar crystal plane, depositing the n-type indium gallium nitride waveguiding layer on or above the n-type gallium nitride layer, depositing the indium gallium nitride active layer on or above the n-type indium gallium nitride waveguiding layer, depositing a p-type indium gallium nitride waveguiding layer on or above the indium gallium nitride quantum wells, and depositing p-type gallium nitride layer on or above the p-type indium gallium nitride waveguiding layer. The method further comprises selecting the semi-polar crystal plane in order to increase a critical thickness of the III-nitride layers grown on the semi-polar crystal plane. The semi-polar crystal plane and the depositing conditions are such that at least one of the III-nitride layers have a surface roughness of less than or equal to 0.75 nm.