I'm not sure how well this would work with your sliding door window but yesterday I placed an order for blackout curtains from here:
BlackoutCurtains.com
One thing they don't show in the photo is that they include a small vallence to hide the hardware & block the light around the hardware.
They also sell blackout shades:
Blackout Shades
They custom make their curtains & tracks to your specs so I won't receive them for about 2 weeks & I don't yet know how well they work.
Have any of you tried the curtains at BlackoutCurtains.com?