For those of you who are interested in modulation characteristics of dpss lasers, I did some measurements. Channel 2: 1 division equals 100mW
equiment used: tektronix tds 210, AN2 ophir power meter, bpw34 photo diode
Minimal 1 hour stabilisation time on infinite heatsink.
TTL input square wave 100mHz
TTL input square wave 1Hz
TTL input square wave 10Hz
TTL input square wave 100Hz
TTL input square wave 1kHz
TTL input square wave 10kHz
TTL input square wave 50kHz
TTL input square wave burst 8x 500uS 10Hz repetition rate
TTL input square wave burst 8x 500uS 100Hz repetition rate
TTL input square wave burst 8x 50uS 100Hz repetition rate
TTL input square wave burst 8x 5mS 1Hz repetition rate
Analog input linearity response at 1kHz typical ramp sample
Analog input linearity response at 1 kHz average of 128 ramps
Analog input sine modulation 1kHz, no dc offset.
Analog input triangle modulation 1kHz, no dc offset.
Analog input sine modulation 10Hz, dc offset to compensate for modulation offset.
Analog input sine modulation 100Hz, dc offset to compensate for modulation offset.
Analog input sine modulation 1kHz, dc offset to compensate for modulation offset.
Analog input sine modulation 10kHz, dc offset to compensate for modulation offset.
I did some pulse width modulation tests too, output power is linear in respect to the duty cycle <80%.
But the results I obtained over 80% dutycycle were unstable.
Output power had a hard time stabilizing >80%
Despite the general opinion that Chinese dpss lasers modulate badly, I think this one does pretty well.
The only thing is does badly is running *unmodulated*. When a new dc voltage is applied, in relatively big steps (>2Volts) , it takes seconds to minutes to stabilize at this new power.