metric Oscillator - Beckman Institute Laser Resource Center

Focussed Back Reflection SakfyLaser optics can be severely damaged even if a small percentage of the output beamis reflected and focussed back into the laser. For instance, a common simple lens,uncoated and positive, reflects about 4% of the beam at each surface. The first surfacereflection back into the laser will diverge, but the second surface reflection willfocus. Intensity at the focus will be very high, usually enough to cause optical damage.Even surfaces with antireflection coatings may reflect back enough focussedenergy to cause damage.To avoid this hazard, minimize focussed back reflections. When they areunavoidable, direct them off-axis to a harmless position or into a beam dump.Damage due to focussed back reflections is not covered by the Spectra-Physics Lasers warranty.Electronics SafetyVoltages present in this unit can cause serious or fatal injury. Onlyqualified personnel should install or perform sewice procedures onthis equipment.Voltage is present on unprotected pins when the unit is operational.No short circuit protector for motor outputs is provided in the unit. Theac input is internally fused.When power is applied. all parts of the circuit should be consideredhazardous.Allow at least ten minutes for capacitors to discharge. Capacitorsremain at high voltages for several minutes after the power is removed.The above warning label applies to any Spectra-Physics manufactured MOP0 pumplaser.Do not connect or disconnect motor or signal cables while ac power isapplied.Do not apply ac power until all the connections have been made correctly.Do not exceed specified input voltages.