There is a port to TensorFlow 2 here. The stuff below worked on earlier versions of TensorFlow.
This is a quick and dirty AlexNet implementation in TensorFlow. You may also be interested in Davi Frossard's VGG16 code/weights.
myalexnet_forward.py -- the implementation itself + testing code for versions of TensorFlow current in 2017 (Python 3).
myalexnet_forward.py -- for older versions of TensorFlowm in Python 2(See this version for a variable rather than placeholder input; you probably want the myalexnet_forward.py version if you want to fine-tune the networks.)