Child-Safe Laser Maze Upgrade

I need our existing laser-maze exhibit adapted before we use it so children can explore it safely It comes with class 3 lasers but we need to change these to class 2 and introduce a system that shuts... (Budget: £200 - £500 GBP, Jobs: Automation, Circuit Design, Control Engineering, Electrical Engineering, Electronics, Embedded Systems, Mechatronics, Microcontroller, Prototyping, Robotics)