Lasers, such as in laser structures, can include two or more semiconductor structures that are substantially identical or that include the same semiconductor material and have substantially the same geometry, such as in closely spaced dual-spot two-beam or quad-spot four-beam lasers. The lasers can also include differently structured current flow or contact structures or different wavelength control structures. For example, current flow or contact structures can be differently structured to prevent or otherwise affect phase locking, such as by causing different threshold currents and different operating temperatures. Exemplary differences include that one laser's semiconductor structure can have an isolated area that does not receive electrical current from a covering conductive layer; conductive layers of two layers can have different thicknesses or lengths; one laser can have a patterned layer with high electrical resistance between its semiconductor structure and a conductive layer; or one laser's semiconductor structure can include regions of high electrical resistance adjacent its contact structure.