Optical imaging system made from a single piece of material

An optical imaging system integrally-formed on a single piece of material, comprising:

• at least a first and second facing, reflective surfaces defining a single optical axis,
• said first reflective surface defining a central aperture through which said optical axis extends and said second reflective surface formed coaxially with said first reflective surface and defining a focus lying on said optical axis,
• radiation impinging on said first reflective surface being reflected therefrom towards said second reflective surface and further reflected from said second reflective surface towards said focus;
• and
• a plurality of elongate rib members integrally formed with said first and second reflective surfaces, said plurality of elongate rib members defining therebetween a plurality of openings communicating with said central aperture, so as to enable passage of radiation reflected from said second reflective surface to said focus thereof.