Click to open expanded view

Lithium Niobate IQ Modulator

The primary role of an IQ modulator is to map complex electrical signals (I and Q components) onto an optical carrier, enabling high spectral efficiency transmission.

Specification

Resources

The 20 GHz x 2 IQ modulator is based on a dual parallel structure of two Mach-Zehnder modulators (DP-MZM) embedded in a Mach Zehnder super-structure (20 GHz x 2). Each internal modulator is designed to have EO bandwidth above 20 GHz. Monitor photodiode is provided for automatic bias control (ABC).

Main Characteristics

• Titanium-Indiffused Waveguide

• X-Cut Lithium Niobate

• Nested Mach-Zehnder Modulators

• Operating at 1525 - 1570 nm

• High Bandwidth operating > 20 GHz each MZM

• Integrated with a monitor photodiode

• Extended operating and storage temperature, -55 ~ +85°C

Application

• OFDM modulation

• QPSK modulation

• QAM modulation

• CS-SSB

• FMCW Autopilot Lidar

Absolute Maximum Rating

Parameters	Symbol	Min.	Max.	Unit
RF Input Power	EPin	-	25	dBm
Optical Input Power	OPin	-	25	dBm
Bias Voltage	VBias	- 40	40	V
Operating Temperature	Top	- 55	85	°C
Operating Temperature Variation Rate	-	-10	10	°C/min
Storage Temperature	Tst	- 55	85	°C
Operating Humidity	-	5	85	%
Leads Soldering Temperature	-	-	250	°C
Leads Soldering Time	-	-	10	s

Technical parameters

Parameters	Symbol	Conditions	Min	Typical	Max	Unit
*Optical*
Operating Wavelength	λ	-	1525	-	1570	nm
Insertion Loss1	IL	-	-	5.0	7.0	dB
Phase-MZ Optical Extinction Ratio	ERP	@ DC	24	-	-	dB
Inner-MZ Optical Extinction Ratio	ERI	@ DC	24	29		dB
Polarization Extinction Ratio	PER	-	20	-	-	dB
Optical Return Loss	RL	-	40	-	-	dB
*Electrical* RF *Ports*
RF Vπ Voltage	RF Vπ	@ 1 kHz	-	-	5.0	V
3dB Electro-optical Bandwidth	S21	wrt 2 GHz	20	23	-	GHz
S21 Ripple	△S21	300 MHz – 20 GHz	-1	-	1	dB
Amplitude difference between Inner-MZs		-	-1	-	1	dB
Skew between Inner MZs		-	-5	-	5	ps
Electrical Return Loss	S11	40 MHz – 17 GHz	-	-12	-10	dB

*Electrical* *Bias* *Ports*
Phase-MZ Bias Vπ Voltage	Bias Vπ	@ 1 kHz	-	7	8	V
Inner-MZ Bias Vπ Voltage		@ 1 kHz	-	7	8	V
Bias Vπ Voltage variation over wavelength		wrt 1550nm	-5	-	5	%
Bias port impedance	Zin-Bias	@ DC	1	-	-	MΩ
*Monitor* *Photodiode*
Monitor Photodiode Reverse Current	-	-		2	-	mA
Monitor Photodiode Forward Current	-	-		10	-	mA
Monitor Photodiode Reverse Voltage	-	-		15	-	V
Responsivity2	-	-	20	-	120	mA/W
Linearity	-	-	-10	-	10	%
Phase Error3	-	PD is not inverting	-5	-	5	Degree

Notes：

1 All specifications given at 25 °C, 1550 nm, unless differently specified. Consider an extra-loss up to 0.3 dB for each FC/APC optical connector.

2 PD responsivity definition (shown as following picture)

· Inner MZs set to maximum transmission.

· The voltage is applied to the outer (phase) MZ

· Responsivity: R= (Im_-3dB) / (Pout_-3dB)

· Im_-3dB is the photodiode current when output optical power is -3dB from maximum.

· Pout_-3dB is the output optical power at -3dB from maximum.

³ The PD phase error is the difference (in modulator phase) between the maximum/minimum of the PD output and the maximum/minimum of the modulator optical output.PD phase error of ± 5° correspond to a phase error of ± 2.8%.

Fiber Specifications

Fiber Type	Corning/Fujikura PM15-U25D (Panda fiber) with 900 µm loose tube
Fiber Length	900 µm loose tube> 1.0 m & bare fiber ≥ 5cm (W/O Connector)
Fiber Length	900 µm loose tube> 0.9 m (With Connector)
Minimum Bending Radius of Fiber	15 mm

Pin-Out Information

Pin	Name/Description	Note	Pin	Name/Description	Note
1	RF. 1	RF Input (SMPM male)	7	Bias PH+	Bias Phase +V
2	RF. 2	RF Input (SMPM male)	8	Bias PH-	Bias Phase -V
3	Bias 2+	Bias wrt RF.2 +V	9	PD Cathode
4	Bias 2-	Bias wrt RF.2 -V	10	PD Anode
5	Bias 1+	Bias wrt RF.1 +V	11	GND	Ground
6	Bias 1-	Bias wrt RF.1 -V

Note: The pin# 3&4, 5&6, 7&8 pin pair doesn’t need to be exact as above table, but any pin pair just need to be of opposite voltage.

Flammability rating

The fiber pigtails are rated UL 94 V-0 (Fujikura fiber) or are compliant to ASTM D-2863-87 requirements (Corning fiber SMF-28), Boots, Loose tube and Connectors are UL94 V-0 rated.

Reliability Requirements

This modulator is designed to meet Telcordia GR-468-Core requirements and hermetically sealed.

Ordering Information: HC- IQ-40-A-B-C-D

A	B	C	D
Wavelength	Fiber type	Fiber length	Connector
C= C band	PP: PM-PM	1: 1m	00: None
		09:0.9m	FA: FC/APC
		05:0.5m	FU: FC/UPC

If you need more support , Please contact us .

Resources

Lithium Niobate IQ Modulator