Method for improvement of beam quality and wavelength stabilized operation of a semiconductor diode laser with an extended waveguide

A semiconductor optoelectronic device comprising:

• a) a vertical resonator further comprising an extended vertical waveguide extended in the vertical direction over a thickness exceeding three times the wavelength of light in the vacuum;
• b) a light-generating element capable to generate optical gain when an injection current is being injected to said light-generating layer when a forward bias is applied, wherein
• said light generating layer is located in a position within said extended vertical waveguide, wherein the distance from said light generating element to the top boundary of said extended vertical waveguide does not exceed one quarter of the thickness of said extended vertical waveguide;
• c) a substrate, wherein the relative positioning of said extended vertical waveguide and said substrate is selected from two alternatives:
• i) said extended vertical waveguide is located above said substrate;
• and
• ii) said substrate is a bottom part of said extended vertical waveguide;
• and
• wherein vertical optical modes of said extended vertical waveguide include
• A) at least one extended vertical optical mode extended over the entire thickness of said extended vertical waveguide and
• B) at least one localized vertical optical mode localized at said light generating element,
• wherein said at least one localized vertical optical mode has a localization length,
• wherein said localization length does not exceed one half of the thickness of said extended vertical waveguide;
• and;
• d) at least one stripe located on a side from said extended vertical waveguide opposite to said substrate;
• and
• e) a longitudinal resonator, further confining said vertical resonator in the longitudinal direction, said longitudinal resonator further comprising
• i) a first facet, and
• ii) a second facet distinct from said first facet, and
• iii) a resonator length defined as a distance between said first facet and said second facet, and
• wherein at least one additional means is provided, wherein said additional means is selected from the group consisting of:
• A) setting said resonator length equal to the length of the return path of at least one of said one or a few said vertical optical mode multiplied by one of optimum geometrical factors, and
• B) introducing an additional structural element aimed to prevent generating a laser light in parasitic optical modes;
• wherein said additional structural element is selected from the group consisting of:
• x) an additional structural element of a first kind intersecting in the vertical plane said at least one stripe over a thickness exceeding one quarter of said localization length of said localized vertical optical mode, and
• xx) an additional structural element of a second kind not intersecting said at least one stripe and intersecting said extended waveguide in the vertical plane over a thickness exceeding one quarter of said thickness of said extended waveguide, and
• xxx) an additional structural element of a third kind that provides at least one unpumped section, and
• xxxx) an additional structural element of a fourth kind, wherein said additional structural element of a fourth kind is a coating deposited on at least one said facet, and
• xxxxx) any combination of x) through xxxx), and
• C) any combination of A) and B);
• wherein said at least one additional means is selected such that to reach a goal selected from the group consisting of:
• I) suppressing light emission in said at least one localized vertical optical mode,
• II) suppressing light emission in at least one parasitic lateral optical mode, and
• III) improvement of the wavelength selectivity of the light emission from said semiconductor optoelectronic device;
• and
• IV) a combination of I) through III).