u/PeppersONLY

I have a setup with a OLED display with a linear polarizer that is directed at a PBS with a quarter wave plate inbetween. A concave mirror at the bottom reflects light back up to the PBS. Everything works okay except the image produced back at the PBS has ghosting and I see a second slightly dimmer and offset image. Could this be because I bought a relatively cheap PBS off aliexpress that does not have a AR coating? All these components are mounted on a 3d printed sliding structure which may cause minor inconsistencies with alignment. If the AR coating is the issue, is there a way to add it as a separate component?

https://preview.redd.it/j8zmdxa3uz1h1.png?width=1806&format=png&auto=webp&s=1eeae25da546c89f93dc07551fc8dc494c3e009d

I am trying to replicate the optics setup in the image above. Everything is similar except I have a OLED display with a linear polarizer as the light source and my reflective surface is a concave mirror. Everything works okay without the QWP and light is visible through the PBS but when the QWP is added at 45deg of the fast axis, the image through the PBS is blurry, "smothered out", and unfocused? Why could this be happening if all optical components are for broadband visible light waves?

PBS: https://www.aliexpress.us/item/3256802176498685.html
Linear polarizer: https://www.amazon.com/dp/B0D2DK3XV9

I have a OLED display oriented facing towards a PBS with a linear polarizer in-between. From my understanding, the light should go all through the PBS and none should be reflected if the linear polarizer is oriented properly. However, no matter the orientation of the linear polarizer, I can still see the light from the display being reflected at the PBS. The only change really is at some 90* intervals it appears slightly dimmer but that's all. Is there something wrong with this setup or maybe the components I have aren't the right spec?

I am ordering a small glass disc off Alibaba which is no more than a pound and its $5 but they are saying DDP shipping to U.S is $42. Is this accurate or am I getting ripped off.

I am ordering a small glass disc off Alibaba which is no more than a pound and its $5 but they are saying DDP shipping to U.S is $42. Is this accurate or am I getting ripped off.