IR laser line-of-sight alignment

A method of visually aligning an optical instrument that simultaneously operates at two different wavelengths where said first wavelength is in the visible photopic electromagnetic spectral region and said second wavelength is outside the visible photopic electromagnetic spectral region, said optical instrument consisting of a telescope operating at said first wavelength and a laser operating at said second wavelength and said method comprising:

• (a) employing a first plate having a first reticle pattern, said first plate being located at the eyepiece of said telescope, said first reticle pattern being in focus when viewed through said eyepiece;
• (b) inserting a removable retroreflector in the collimated space of said telescope;
• (c) employing a second plate having a second reticle pattern which is positioned in said optical instrument such that when said second reticle pattern is illuminated with light of said first wavelength and said removable retroreflector is inserted in said collimated space of said telescope then said second reticle pattern will be in focus and superimposed on said first reticle pattern when viewed through said eyepiece;
• and
• (d) aligning the focused image of said second reticle pattern onto said first reticle pattern displayed at said eyepiece.

An optical element for visually aligning an optical instrument that simultaneously operates at two different wavelengths where said first wavelength is in the visible photopic electromagnetic spectral region and said second wavelength is outside the visible photopic electromagnetic spectral region, said optical instrument having a first plate having a first reticle pattern, said first plate being located at the eyepiece of said optical instrument, said first reticle pattern being in focus when viewed through said eyepiece, said optical element comprising a second plate which has a second reticle pattern on one side and a clear field stop on the opposite side, the position of said second plate being such that when said second reticle pattern is illuminated with light of said first wavelength and a removable retroreflector is inserted in said optical instrument, then said second reticle pattern will be in focus and superimposed on said first reticle pattern when viewed through said eyepiece such that alignment of said optical instrument can be accomplished by aligning the focused image of said second reticle pattern onto said first reticle pattern displayed at said eyepiece, and the thickness and orientation of said second plate being such that when said clear field stop is illuminated with light of said second wavelength and said removable retroreflector is inserted in said optical instrument, then said clear field stop will be in focus and superimposed on said first reticle pattern when viewed through said eyepiece.