Laravel 4在数据透视表上的关系

Schema for Professor-Teaching-Subject

Above is the current schema that is on my mind.

Each professor (faculty), will teach more than one subjects. The faculties_has_subjects table is the pivot table linking the two. On top of that, the pivot relation should have an attribute to store which semester it was taught in.

Sample data for the semesters table is:

+----+------------------+
| id | name             | 
+----+------------------+
| 1  | Fall 2010-2011   |
+----+------------------+
| 2  | Winter 2010-2011 |
+----+------------------+
| 3  | Fall 2011-2012   | 
+----+------------------+
| 4  | Winter 2011-2012 | 
+----+------------------+

How do I use laravel's Eloquent ORM to extract the following details for a particular faculty.

Subjects Taught
Semester in which each subject was taught

I could do it easily if instead of semesters_id, there was semester_name directly. But since this is a foreign key in the pivot table itself, how do I use Eloquent ORM with it?

Thanks!