Reticle overlaid within a galilean magnification system
An optical system is provided, including a Galilean magnification device, including an objective lens and an eyepiece lens arranged along an axis. One of the objective lens and the eyepiece lens is a positive lens and the other is a negative lens, thereby defining an image working distance; a reticle device within the Galilean magnification device, including a holographic element, the reticle device being configured to receive light for illuminating the holographic element from off the axis and to direct light from the holographic element on the axis, so that light from the holographic element is set at the image working distance by the eyepiece lens. There is also described a method for recording a holographic reticle for use in a Galilean magnification device.
1. An optical system, comprising:
a Galilean magnification device comprising an objective lens and an eyepiece lens arranged along an axis;
wherein one of the objective lens and the eyepiece lens is a positive lens and the other is a negative lens, thereby defining an image working distance;
a reticle device in the Galilean magnification device, the reticle device comprising a holographic reticle element recorded in a holographic material as an interference pattern;
wherein the reticle device is configured to receive light to illuminate the holographic reticle element from off the axis and to diffract the received light through the holographic reticle element and onto the axis to replay an image of the holographic reticle element, so that light from the holographic reticle element is set at the image working distance by the eyepiece lens to allow the replayed image of the holographic reticle element to be viewed; and
wherein the holographic element further comprises a hologram or holographic optical element positioned along the axis between the objective lens and the eyepiece lens.
2. The optical system of claim 1 , wherein the optical system is configured so that light from the objective lens is set at the image working distance by the eyepiece lens.
3. The optical system of claim 1 , wherein the reticle device further comprises a replay light source configured to illuminate the hologram.
4. The optical system of claim 1 , wherein the reticle device comprises:
a backlit or light source reticle positioned off the axis; and
a holographic optical element lens arranged to receive light from the backlit or light source reticle, and direct the diffracted light towards the eyepiece lens.
5. The optical system of any one of claim 1 , wherein the Galilean magnification device is a reverse Galilean telescope so that the objective lens is a negative lens and the eyepiece lens is a positive lens, and wherein the reticle device is configured so that light diverges towards the eyepiece lens.
6. The optical system of claim 1 , wherein the holographic reticle element is recorded in the holographic material with zero parallax.
7. The optical system of claim 1 , wherein the holographic reticle element is viewed with zero parallax.