Here is a SETI Institute seminar on a lesser known way to detect and measure exoplanets: Detecting Exoplanetary Systems with Micolensing – Scott Gaudi (SETI Talks)
From the caption:
Measurements of the demographics of exoplanets over a range of planet and host star properties provide fundamental empirical constraints on theories of planet formation and evolution. Because of its unique sensitivity to low-mass, long-period, and free-floating planets, microlensing is an essential complement to our arsenal of planet detection methods.
Dr. Gaudi will review the microlensing method, and discuss results to date from ground-based microlensing surveys. Also, Dr. Gaudi will motivate a space-based microlensing survey with WFIRST-AFTA, which when combined with the results from Kepler, will yield a nearly complete picture of the demographics of planetary systems throughout the Galaxy.