A bandwidth selection mechanism comprising: a dispersive optical element grating having a body including a reflective face of dispersion including an area of incidence extending in a longitudinal axis direction along the reflective face of the dispersive optical element grating; a first end block, disposed at a first longitudinal end of the body; a second end block, disposed at a second longitudinal end of the body, the second longitudinal end being opposite the first longitudinal end; and a first actuator (702, 802) mounted on a second face of the dispersive optical element grating, the second face being opposite from the reflective face, the first actuator (702, 802) having a first end coupled to the first end block and a second end coupled to the second end block, the first actuator (702, 802) being operative to apply equal and opposite forces to the first end block and the second end block to bend the body along the longitudinal axis of the body and in a first direction normal to the reflective face of the dispersive optical element grating; characterized by a second actuator (804,1570) mounted on a third face of the dispersive optical element grating, the third face being normal to the reflective face, the second actuator (804,1570) having a first end coupled to the first end block with a first flexure (706 A, 706A') and a second end coupled to the second end block with a second flexure (706B, 706B'), the first actuator (702, 802) being operative to apply equal and opposite forces to the first end block and the second end block to bend the body along the longitudinal axis of the body, in a second direction perpendicular to the reflective face of the dispersive optical element grating, the second direction also being perpendicular to the first direction, the second actuator including a pressurized fluid force application mechanism. a dispersive optical element grating having a body including a reflective face of dispersion including an area of incidence extending in a longitudinal axis direction along the reflective face of the dispersive optical element grating; a first end block, disposed at a first longitudinal end of the body; a second end block, disposed at a second longitudinal end of the body, the second longitudinal end being opposite the first longitudinal end; and a first actuator (702, 802) mounted on a second face of the dispersive optical element grating, the second face being opposite from the reflective face, the first actuator (702, 802) having a first end coupled to the first end block and a second end coupled to the second end block, the first actuator (702, 802) being operative to apply equal and opposite forces to the first end block and the second end block to bend the body along the longitudinal axis of the body and in a first direction normal to the reflective face of the dispersive optical element grating; characterized by a second actuator (804,1570) mounted on a third face of the dispersive optical element grating, the third face being normal to the reflective face, the second actuator (804,1570) having a first end coupled to the first end block with a first flexure (706 A, 706A') and a second end coupled to the second end block with a second flexure (706B, 706B'), the first actuator (702, 802) being operative to apply equal and opposite forces to the first end block and the second end block to bend the body along the longitudinal axis of the body, in a second direction perpendicular to the reflective face of the dispersive optical element grating, the second direction also being perpendicular to the first direction, the second actuator including a pressurized fluid force application mechanism.