 
 <prompt> Wetin dem dey call di property wey material get wey fit make visible light split into two or more distinct beams of different wavelengths? <response>: ```wia one prime dey show di real part and two prime dey show di imaginary part, Z(ω) na di complex impedance wen di dielectric dey present, Ccmplx(ω) na di so-called complex capacitance wen di dielectric dey present, and C0 na di capacitance without di dielectric. (Measurement "without di dielectric" for principle mean say measurement for free space, wey be goal wey no fit reach as even di quantum vacuum dey predict to show nonideal behavior, like dichroism. For practical purposes, when measurement errors dey taken into consideration, often measurement for terrestrial vacuum, or simply calculation of C0, dey accurate sotay.)``` 