High index glass and devices incorporating such

A glass having a refractive index of greater than 1.65 at a wavelength λ, where λ=587.6;

• the glass having a density of no more than 4.05, and comprising
• SiO2, 20-55 wt %
• ZrO2, 5-10 wt %;
• Na2O 2-5 wt %
• K2O5 4-9 wt %;
• CaO 3.5-8.5 wt %;
• Sr 0 to 1 wt %
• BaO 10-20 wt %;
• La2O3 0.2 to 2 wt %;
• Nb2O5 0.5 to 3 wt %;
• TiO2 12-20 wt %
• F 0-1 wt %.

A glass comprising:

• a refractive index N of greater than 1.65 at a wavelength λ, where λ=587.6 nm;
• a glass density of not more than 4.2 g/cm3;
• Abbe number Vd greater than 30;
• the glass comprising greater than 0.01 wt % of at least one rare earth oxide having an atomic number of 58 or higher.

A multilayer light guide device comprising:

• (i) (a) a first input grating being structured and positioned to couple a first wavelength band of a visible wavelength spectrum to the a glass light guide, the first glass light guide being structured to transmit light in the first wavelength band towards an first output grating, along a first optical path situated between the first input grating and the first output grating, and (b) a first light filtering agent situated in the first optical path between the first input grating and the first output grating,
• wherein said glass light guide in conjunction with said first light filtering agent is structured to filter out at least 50% of light in a least one light wavelength λa1 situated within the first wavelength band propagating toward the first output grating;
• (ii) (a) second glass light guide being structured to transmit light in one or more wavelengths from a second input grating towards a second output grating, along a second optical path situated between the second input grating and the second output grating;
• wherein the first input grating is structured and positioned to couple light to the second input grating;
• and the second input grating is structured and positioned to receive light coupled from the first input grating and to transmit the received light to the second glass light guide, and (b) a second light filtering agent situated in the second optical path between the second input grating and the second output grating;
• wherein said second glass light guide in conjunction with said second light filtering agent is filtering at out least 50% of light in at least one light wavelength λa2 that propagates toward the second output grating;
• and
• wavelengths λa1, and λa2 are different from one another;
• wherein the first and second light filtering agent comprises light absorbing dopants.