The most  acceptable definition for contemporary literature is two dimensional.

First, there is the period of time in which the work is authored--during or after the 1960s. Works authored before that era of cultural  revolution are generally known as  classic literature.

The second dimension is the style of writing and the subject matter.  Rules, taboos, conventional perceptions, and reality are often cast aside in presentation of contemporary works (yet are often the subject or backdrop of the story).

As a judge presiding over lawsuits in an entire different genre said, "I know it when I see it."

• Introduction to Science Fiction
  A Wikipedia resources.

• New Wave Science Fiction
  A Wikipedia resource

• Introduction to Cyberpunk
  A Wikipedia resource.

• Introduction to Counterculture Literature
  A Wikipedia resource.