Employers are often unfamiliar with F-1 employment options like Optional Practical Training and Curricular Practical Training. They might assume that hiring an F-1 student requires them to immediately initiate work visa sponsorship, which is not the case. You might need to educate potential employers about your ability to obtain employment authorization with the help of our office and/or U.S. Citizenship and Immigration Services.
Here is a letter you might find useful to give to potential employers at an interview or in other communications. It explains in very general terms the F-1 employment options.