It has the following specifications:
Model: AQ4321A
Wavelength range: 1480 to 1580 nm
Wavelength set resolution: 0.001 nm
Wavelength stability: ±100 MHz/h (±0.8 pm/h) (typ.) (2, 3)
Absolute wavelength accuracy:
±0.01 nm 2, 3, 4, 8)
±0.015 nm, ±0.01 nm (typ.) (2, 3, 4, 7)
Relative wavelength accuracy: ±0.01 nm (typ.) (2, 3, 4, 7)
Spectral width:
Narrow 200 kHz (typ.) (1 MHz or less)
Wide 200 MHz (typ.) (100 MHz or more)
SMSR: 50 dB or more (optical output: +7 dBm, 1550 nm)
Optical output:
+10 dBm (typ.) peak (D Model: +7 dBm (typ.) peak)
+7 dBm or more, 1520 to 1570 nm
+5 dBm or more, 1500 to 1580 nm
+3 dBm or more, 1480 to 1580 nm
Settable optical output range: 20 dB or more (0.1 dB steps, at peak wavelength)
Optical output stability:
5 min ±0.01 dB or less (2, 9)
1 h ±0.05 dB or less (5, 9)
8 h ±0.3 dB or less (6, 9)
Optical output accuracy: ±1 dB or less (4, 9)
Optical output reproducibility: ±0.04 dB, optical output fixed (4, 5, 9)
Optical output level flatness: ±0.1 dB (4,9) (1500 to 1580 nm)
RIN: -145 dB/Hz (typ.)
Internal modulation (CHOP):
Set frequency: 0.2 to 300 kHz (10)
Set resolution: 10 Hz, 100 Hz, 1 kHz, 10 kHz, 100 kHz 10)
External modulation (CHOP):
Set frequency: 0.2 to 300kHz (10)
Set resolution: –
Direct modulation: 5% or less (Modulation frequency: 100 kHz to 300 MHz, modulation input level: 0 dBm or less)
Wavelength sweep speed: 100 nm/sec (max.)
Applicable optical fiber: SMF (10/125 µm)
Applicable connector: FC/PC (Standard), optical return loss: 50 dB or more

Notes
1) The above specifications without any special remarks are results under the following conditions: CW light, at the output point of 2 m-long optical fiber, after warming-up for 1 hour
2) Constant temperature: 23 °C
3) Spectral width: Narrow, Sweep FINE, Opt ATTN Cont = 1
4) Optical output level: +3 dBm
5) Within ±1 °C in the range of 10 to 35 °C
6) 10 to 35 °C
7) 2d (1 hour after wavelength calibration)
8) At 1520 nm wavelength
9) Spectral width: wide
10) Duty: 50 ±5 %