Basically yes (or maybe)
A switched mode regulator will be around 80 to 90% efficient, but that depends to some extent on the drive voltage. Input current depends upon input voltage whilst output current depends upon the specific load demand. Best to look at output wattage to determine input wattage.
Linear regulators are much less efficient. For example if you only want 3 volts and your battery is 12 volts the maximum efficiency will be 25% since 9 volts are being "lost" across the regulator and the input current is slightly greater than the output current.
If possible you'd be better to select a 3volt battery to drive the laser device directly