A method for illumination of a sample in a microscope comprising: projecting a collimated light beam from an optical system to a plane for a total internal reflection fluorescent (TIRF) illumination during a first mode of operation of said optical system; and projecting a convergent light beam from said optical system to said plane during a second mode of operation of said optical system, wherein said projecting said collimated light beam comprises: routing a first light bundle from a light source to an orthogonal pair of galvanometer scanning mirrors; and controlling said orthogonal pair of galvanometer scanning mirrors to: (a) direct said first light bundle to a first light path in said optical system along which said first light bundle propagates to produce said collimated light beam; and (b) control a trajectory of said first light bundle in said first light path to steer said collimated light beam through said plane at a designated incidence angle in a circular path, and wherein said projecting said convergent light beam comprises: routing a second light bundle from said light source to said orthogonal pair of galvanometer scanning mirrors; and controlling said orthogonal pair of galvanometer scanning mirrors to: (a) direct said second light bundle to a second light path in said optical system along which said second light bundle propagates to produce said convergent light beam; and (b) control a trajectory of said second light bundle in said second light path to steer said convergent light beam to a target position in said plane, wherein (i) during said first mode of operation: (a) receiving said first light bundle at an optical device comprising a mirror having an aperture therethrough, via said first light path; and (b) directing said first light bundle from said optical device to a downstream light path that leads to said plane; and (ii) during said second mode of operation: (a) receiving said second light bundle at said optical device via said second light path; and (b) directing said second light bundle from said optical device to said downstream light path. projecting a collimated light beam from an optical system to a plane for a total internal reflection fluorescent (TIRF) illumination during a first mode of operation of said optical system; and projecting a convergent light beam from said optical system to said plane during a second mode of operation of said optical system, routing a first light bundle from a light source to an orthogonal pair of galvanometer scanning mirrors; and controlling said orthogonal pair of galvanometer scanning mirrors to: (a) direct said first light bundle to a first light path in said optical system along which said first light bundle propagates to produce said collimated light beam; and (b) control a trajectory of said first light bundle in said first light path to steer said collimated light beam through said plane at a designated incidence angle in a circular path, and (a) direct said first light bundle to a first light path in said optical system along which said first light bundle propagates to produce said collimated light beam; and (b) control a trajectory of said first light bundle in said first light path to steer said collimated light beam through said plane at a designated incidence angle in a circular path, and routing a second light bundle from said light source to said orthogonal pair of galvanometer scanning mirrors; and controlling said orthogonal pair of galvanometer scanning mirrors to: (a) direct said second light bundle to a second light path in said optical system along which said second light bundle propagates to produce said convergent light beam; and (b) control a trajectory of said second light bundle in said second light path to steer said convergent light beam to a target position in said plane, (a) direct said second light bundle to a second light path in said optical system along which said second light bundle propagates to produce said convergent light beam; and (b) control a trajectory of said second light bundle in said second light path to steer said convergent light beam to a target position in said plane, (i) during said first mode of operation: (a) receiving said first light bundle at an optical device comprising a mirror having an aperture therethrough, via said first light path; and (b) directing said first light bundle from said optical device to a downstream light path that leads to said plane; and (a) receiving said first light bundle at an optical device comprising a mirror having an aperture therethrough, via said first light path; and (b) directing said first light bundle from said optical device to a downstream light path that leads to said plane; and (ii) during said second mode of operation: (a) receiving said second light bundle at said optical device via said second light path; and (b) directing said second light bundle from said optical device to said downstream light path. (a) receiving said second light bundle at said optical device via said second light path; and (b) directing said second light bundle from said optical device to said downstream light path.