It was ebay item number 161130761148 but if you are struggling, a re-focussed 405nm laser pointer is pretty similar and that's what I started with. 

ok you buy from ebay, good i am thinking of using optics for focusing laser to 0.025mm dot and i may need your help

Let me know - I'm pretty inexperienced in anything of that precision but will try 

 I am making something similar based on this http://www.g3gg0.de/wordpress/uncategorized/um2-laser-addon-part-2/

But with a corexy grbl. I used a much less powerful laser (few mW 405nm laser pointer) and managed to draw the circuit trace outline on heat sensitive receipt paper. I'm going to try photosensitive pcb film next and have a 20mW laser in the mail from China.

Hi, sorry for late reply, i have already tried this and thanks for the link to machine , when will you get the 20mW laser, i have got myself 100mw & 1W laser and i wanted to use semitransparent object to reduce its strength and try again. i am facing the light bleeding from the laser i.e some light bleeds to region surrounding the laser dot this is causing the photo resist to dry out due to this light.
Any idea how can i stop that?

I haven't tried with photoresist yet, still taking the chance to transfer the mechanism to its own frame.  20mW laser is here though. 

Can you please post photos of the laser module and where did you get the laser from(website) like banggood etc