Driving a laser module from 5V supply
You linked to the datasheet, but apparently didn't read it.  It's not very good, but enough basic information is there.  The typical operating point is 3.0 V at 25 mA.  If you are using a 5 V supply with a resistor, then the resistor will drop 2 V.  2V / 25mA = 80&Omega;.  How you came up with 1 k&Omega;, 470 &Omega;, and 200 &Omega; as series resistors is completely beyond me.

Directly connecting this laser to a 5 V supply is a really bad idea.  The datasheet only lists the typical voltage, which is 3.0 V.  It does show the typical current as 25 mA and the maximum as 35 mA.  How is directly connecting this thing to a 5 V supply going to ensure 35 mA is not exceeded?  You may have damaged the device, even if it appears to operate.

Try the common value of 82 &Omega; in series with the 5 V supply and measure the voltage accross the module.  It should be about 3 V.  To not exceed 35 mA, the voltage accross the resistor must not exceed 35mA * 82&Omega; = 2.87 V, which also means the voltage accross the module when powered thru this resistor and a 5 V supply should be at least 2.13 V.