Context: Bell believed the photophone's principles were his life's "greatest achievement", telling a reporter shortly before his death that the photophone was "the greatest invention [I have] ever made, greater than the telephone". The photophone was a precursor to the fiber-optic communication systems which achieved popular worldwide usage in the 1980s. Its master patent was issued in December 1880, many decades before the photophone's principles came into popular use.

Question: What did Bell call the best thing he ever made?
Answer: The photophone

Question: Bell thought the photophone was better than what famous invention?
Answer: telephone

Question: What modern technology takes the next step from the photophone?
Answer: fiber-optic communication

Question: When was fiber-optics first patented?
Answer: 1880

Question: In what decade did fiber-optics become widely used?
Answer: 1980s