Lead-bismuth glasses for acoustooptic and magnetooptic devices

DETAILED DESCRIPTION Having thus described the invention, what is claimed is: 1.
A homogeneous glass composition having an index of refraction of at least about 2.
1, a longitudinal sound velocity of less than about 4 mm/.
mu.
sec, an acoustic loss of less than about 6 db/cm at 20 MHz, a Verdet constant greater than about 0.
10 min/Oe-cm at 0.
63.
mu.
m and an optical loss of less than about 10% cm when measured at a wavelength between 1 and 2.
mu.
m said glass consisting essentially of:
Composition
Mole %
______________________________________
GeO.
sub.
2
5-32
B.
sub.
2 O.
sub.
3
1.
5-18
PbO 30-60
Bi.
sub.
2 O.
sub.
3
10-41
______________________________________
wherein: Bi.
sub.
2 O.
sub.
3 +PbO .
gtoreq.
65% mole and ##EQU3## 2.
The glass composition of claim 1 wherein 1 .
ltoreq.
PbO/Bi.
sub.
2 O.
sub.
3 .
ltoreq.
3.
3.
The glass composition of claim 1 wherein PbO/Bi.
sub.
2 O.
sub.
3 is about 2.
4.
The glass composition of claim 1 which consists essentially of:
Component
Mole %
______________________________________
GeO.
sub.
2
9-30
B.
sub.
2 O.
sub.
3
2-15
PbO 34-54
Bi.
sub.
2 O.
sub.
3
20-35.

______________________________________
5.
In a device for the acousto-optical modulation of a beam of electromagnetic radiation comprising a glass element, means for propagating longitudinal sonic wave through said element in a propagating a beam of electromagnetic radiation through said element in a predetermined direction so as to cause deflection of said beam by acousto-optical interaction with the sonic waves, the improvement wherein said glass element has the composition of claim 1.
6.
In a device for the acousto-optical modulation of a beam of electromagnetic radiation comprising a glass element, means for propagating longitudinal sonic wave through said element in a predetermined direction, and means for propagating a beam of electromagnetic radiation through said element in a predetermined direction so as to cause deflection of said beam by acousto-optical interaction with the sonic waves, the improvement wherein said glass element has the composition of claim 2