[analog31]

Indeed the LT1028 datasheet shows a BF862 JFET at the front end of a photodiode preamp using the LT1018.

The reason why we're at a plateau of op amp noise performance is that the current crop of chips are operating very close to the theoretical limit for both bipolar and JFET input devices.

Ironically I use a LT1028 in a homemade circuit for measuring the noise of things that are more noisy.

[zsmi]

Also, a lot of the newer low noise op amps want much better frequencies characteristics and more GBW as they're primary application is sensors. Take for example the ADA4817. It has very comparable noise characteristics but is quite a lot faster.