BR optics

 from Canon, Blue spectrum refractive optics

BR optics is based on a new organic optical material, developed by reexamining lens material from its molecular structure. This new lens material features unique anomalous dispersion characteristics that are capable of greatly refracting blue light (short wavelengths spectrum), which has traditionally been difficult to focus on a single point. Incorporation of a BR lens, consisting of BR optics sandwiched between concave and convex glass lenses, makes it possible to control the path of blue light (short wavelength spectrum), producing clear, sharp images by thoroughly reducing chromatic aberration.

Nikon also introduced Nikkor z 400mm f/4.5 VR S telephoto lens with SR lens:

The lens is constructed of 19 elements in 13 groups, including one Extra-low Dispersion (ED) element, two Super ED elements and one Short-wavelength Refractive (SR) lens element. The SR element refracts blue light more than green or red, helping to control longitudinal aberrations...

Nikon patent: WO2020217791A1 

dpreview

The so-called short wavelength refractive (SR) glass., from hikari

70-200mm uses: J-SFH4 nd：1.663820 vd：27.35

120-300mm uses: J-SFH5 nd：1.755750 vd：24.71

from R.A.Buchroeder,  Arizona U,

it is related to GLAPO(Glass-Liquid Apochromatic objective), patent 5731907, auxillary lens with liquid element for correcting secondary color

...substantially abnormal dispersion liquid being selected to produce a substantially zero focal length change in the achromatic optical system over a wavelength band of approximately 0.43 micron to 0.61 micron

material of dispersion liquid: CARGILLE 642134 

another example: 

Larson 3.8 m f/1.2 with GLAPO, using another exotic liquid Cargille 550203