Limitations of Arduino Voltage Pulse? (TTL)
Are Arduino based boards capable of producing pulses in the range of MICROseconds (usecs)? 


This can be achieved in a number of ways

Some examples:


Using the micros() function.
This returns the value of a counter which is in microsecond units and which is incremented every 4 or 8 microseconds (see below) 


They say


  Returns the number of microseconds since the Arduino board began running the current program. This number will overflow (go back to zero), after approximately 70 minutes. On 16 MHz Arduino boards (e.g. Duemilanove and Nano), this function has a resolution of four microseconds (i.e. the value returned is always a multiple of four). On 8 MHz Arduino boards (e.g. the LilyPad), this function has a resolution of eight microseconds.



Here is a 2011 SE EE question which should be useful - Arduino: better microsecond resolution than micros()?
Answers cover the direct use of the hardware timers. 





You can use the delayMicroseconds() function which delays all actions for the defined period. While limiting this may be useful in some simple applications.
You can write your own loop with known time per loop. This would allow you to perform various simple functions while you wait.