  A judicious design of gain and loss leads to counterintuitive wave phenomena
that are inaccessible by conservative systems. Notably, such designs can give
rise to laser-absorber modes and anisotropic transmission resonances. Here, we
analyze the emergence of these phenomena in an optical scatterer with sinusoid
gain-loss modulation that is subjected to monochromatic oblique waves. We
derive an analytical solution to the problem, with which we show how the
scatterer parameters, and specifically the modulation phase and incident angle,
constitute a real design space to access these phenomena.
