OFA

There are various versions of Optical Fiber based Amplifiers (OFA) Erbium Doped Fiber Amplifiers (EDFAs) which can be used for multichannel amplification up to 96 Channels.

Front panel

The following figure shows the front panel view of Single OFA (OFA-C-S20-VG) and Dual OFA (OFA-C-D20-LVG) cards with default filler.

OFA-C-S20-VG single port variant - Front panel

OFA-C-S20-VG dual port variant - Front panel

Visual indicator details

The visual indicators on the OFA card has two LEDs - the Sts (Status) LED indicate the status of the card and the Act (Active) LED indicates whether the card is active or not.

OFA - Active and status LEDs indications

Card State	Status LED	Active LED
Card initialization: State before the card initialize is complete on card insertion.	Amber (Steady)	Amber (Steady)
Card in service: Initialization complete and card in service.	Green (Steady)	Green (Steady)
Card mis-match: Node has already configured the slot with some other card.	Amber	Amber
Card failed during boot up.	Red	Amber
Card failed while in-service.	Red	Green
Improper jack in of the card	Green (Blinking)	Green (Blinking)
Hard Reset: All devices reset, FPGAs cleared and reprogrammed. Goes to initializing state next.	Amber	Amber
Soft Reset: Software is restarted, devices are reinitialized with provisioning. Goes to initializing state next.	Green	Green
Early Ejector LED status: One ejector is removed (contains one ejector switch in right).	OFF	Amber

There are LEDs provided for Amplifier input (Rx) port and output (Tx) port. LED is either OFF or Glow RED.

LED OFF: Indicates that there are no alarms.
LED Glow RED: Indicates that the alarm exists.

OFA card types

Fixed Gain EDFA: Fixed gain EDFA design gives the flat gain for all DWDM channels at the designed gain known as Designed Flat Gain (DFG). When the gain is changed other than DFG, each channel is amplified differently giving a gain tilt. Following card types are available:

Fixed Gain OFA Card Types

Fixed Gain OFA Description	Model number
Fixed Gain amplifier, single module with 17dBm output power in C-band.	OFA-C-S17-FG
Fixed Gain amplifier, dual modules with 17dBm output power in C-Band.	OFA-C-D17-FG
Fixed High Gain amplifier, single module with 20dBm output power in C-band.	OFA-C-S20-HG
Fixed High Gain amplifier, dual modules with 20dBm output power in C-band.	OFA-C-D20-HG
Fixed Low Gain amplifier, single module with 20dBm output power in C-band.	OFA-C-S20-LG
Fixed Low Gain amplifier, dual modules with 20dBm output power in C-band.	OFA-C-D20-LG

Variable Gain EDFA: Variable Gain EDFA can give the flat gain for all channels over designed gain range. When the gain is changed other than DFG, each channel is amplified differently giving a gain tilt. This tilt can be compensated by adjusting the gain tilt setting. Following card types are available:

Variable Gain OFA Card Types

Variable Gain OFA Description	Model number
Variable Gain amplifier, single module with 20dBm output power in C-band.	OFA-C-S20-VG
Variable Gain amplifier, dual modules with 20dBm output power in C-band.	OFA-C-D20-VG
Low Variable Gain DWDM amplifier, single port with 20dBm output power in C-band.	OFA-C-S20-LVG
Low Variable Gain DWDM amplifier, dual ports with 20dBm output power in C-band.	OFA-C-D20-LVG
Mixed Variable Gain (Low and High Gain) DWDM amplifier, dual ports with 20dBm output power in C-band.	OFA-C-D20-MVG

Variable gain with Mid Stage Access EDFA: Following card types are available:

Variable gain with Mid Stage Access OFA Card Types

Variable gain with Mid Stage Access OFA Description	Model number
Variable gain with Mid Stage Access, single module with 20dBm output power in C Band.	OFA-C-S20-MS-VG

Functional description

The different versions of OFA cards mentioned above are used for optical amplification in POTP and DWDM configuration of the product. The schematic diagram of the cards with single and dual module varieties is as follows:

Single and Dual type of OFA Cards

The schematic diagram of variable gain OFA is as follows:

Single and Dual LVG OFA

The schematic diagram of mid-stage OFA is as follows:

Single type of OFA Card

The following schematic diagram describes the connectivity of the OFA cards with OSC filter module which can be plugged into OFA card. The fiber connectivity between the OFA cards and the OSC filter module is external to the cards:

OFA and OSC Filter Connectivity

The fiber connectivity between the OFA cards and the OSC filter module is external to the cards:

OFA and OSC Filter Connectivity

Typical specifications

Typical specification of the fixed gain and the variable gain OFAs are as follows:

Support C-band DWDM amplification.
Single card supports both East and West applications at ILA location.
Single card can be configured as Mid-Stage-Access EDFA.
Fixed gain and variable gain versions available.
Output monitor port with 1 % tap.
Card supports APR functionality.
Support for AGC mode and optional APC and ACC operating modes.
Meet Class 1M safety requirements.

The following table summarizes the different parameters of fixed gain OFA card and its typical values:

Fixed Gain OFA Card parameters and typical values

Specification	Unit	OFA-C-S17-FG & OFA-C-D17-FG	OFA-C-S20-HG & OFA-C-D20-HG	OFA-C-S20-LG & OFA-C-D20-LG
Total operating wavelength range	nm	1529 nm to 1565 nm	1529 nm to 1565 nm	1529 nm to 1565 nm
Total operating wavelength range	THz	191.6 to 195.9	191.6 to 195.9	191.6 to 195.9
Input power range	dBm	-5 to -35	-5 to -35	-5 to -35
Design Flat Gain (DFG)	dB	23	26	22
Noise Figure, at DFG and minimum input	dB	5.5	5.5	5.5
Output power range	dBm	-5 to 17	-5 to 20	-5 to 20
Output Power Monitor port (-20dB)		Available	Available	Available
Polarization dependent gain	dB	0.5	0.5	0.5
Polarization mode dispersion	ps	0.7	0.7	0.7
Optical return loss	dB	>40	>40	>40
Operating modes	-	AGC, APC, ACC	AGC, APC, ACC	AGC, APC, ACC
Input voltage	V	-48	-48	-48
Maximum power consumption	W	11 W for OFA-C-S17-FG	16 W for OFA-C-S20-HG	16 W for OFA-C-S20-LG
Maximum power consumption	W	20 W for OFA-C-D17-FG	25 W for OFA-C-D20-HG	25 W for OFA-C-D20-LG
Mechanical dimension	-	One Full slot width	One Full slot width	One Full slot width

The table below summarizes the different parameters of variable gain OFA card and its typical values:

Variable Gain OFA parameters and typical values

Specification	Unit	OFA-C-S20-VG & OFA-C-D20-VG	OFA-C-S20-MS-VG
Total operating wavelength range	nm	1528.77 nm to 1566.72 nm	1528.77 nm to 1566.72 nm
Total operating wavelength range	THz	191.35 to 196.1	191.35 to 196.1
Input power range	dBm	-35 to 5	-35 to 5
Nominal Gain	dB	15 to 30	16 to 28
Extended gain range	dB	30.1 to 33	28.1 to 33
Output power range	dBm	-5 to 20	-7 to 21
Mid-stage Loss	dB	NA	8.5
Noise figure	dB	G≥16dB: 10.7	G≥16dB: 13
		G≥18dB: 8.0	G≥19dB: 8.8
		G≥21dB: 6.5	G≥22dB: 7.3
		G≥24dB: 5.7	G≥25dB: 6.6
		G≥27dB: 5.6	G≥28dB: 5.9
		G≥30dB: 5.5	-
Output power Monitor port(-20db)	-	Available	Available
polarization dependent gain	dB	0.5	0.5
Polarization mode dispersion	ps	0.7	0.7
Optical return loss	dB	>40	>40
Operating modes	-	AGC, APC, ACC	AGC, APC, ACC
Input voltage	V	-48	-48
Maximum Power consumption	W	20 W for OFA-C-S20-VG, 35 W for OFA-C-D20-VG	30 W for OFA-C-S20-MS-VG
Mechanical dimension	-	One Full slot width	One Full slot width

The table below summarizes the different parameters of Lower variable gain OFA card and its typical values:

Lower Variable Gain OFA parameters and typical values

Specification	Units	OFA-C-S20-LVG & OFA-C-D20-LVG	OFA-C-D20-MVG Variable Gain Mode

Specification	Units	OFA-C-S20-LVG & OFA-C-D20-LVG	Port1	Port2
Total operating wavelength range	nm	1528.77 nm to 1566.72 nm	1528.77 nm to 1566.72 nm	1528.77 nm to 1566.72 nm
Total operating wavelength range	THz	191.35 to 196.1	191.35 to 196.1	191.35 to 196.1
Input power range	dBm	-22 to 10	-22 to 10	-35 to 5
Nominal Gain	dB	10 to 20	10 to 20	15 to 30
Extended Gain	dB	NA	NA	NA
Output power range	dBm	-13 to 20	-13 to 20	-5 to 20
Mid-stage Loss	dB	NA	NA	NA
Noise figure	dB	G≥10dB: 10.5	G≥10dB: 10.5	G≥16dB: 10.7
		G≥13dB: 8.0	G≥13dB: 8.0	G≥18dB: 8.0
		G≥15dB: 6.5	G≥15dB: 6.5	G≥21dB: 6.5
		G≥18dB: 5.5	G≥18dB: 5.5	G≥24dB: 5.7
		--	--	G≥27dB: 5.6
		--	--	G≥30dB: 5.5
Output power Monitor port(-20dB)	-	Available	Available	Available
polarization dependent gain	dB	0.3	0.3	0.5
Polarization mode dispersion	ps	0.3	0.3	0.7
Optical return loss	dB	>40	>40	>40
Operating modes	-	AGC, APC, ACC	AGC, APC, ACC	AGC, APC, ACC
Input voltage	V	-48	-48
Maximum Power consumption	W	25 for OFA-C-S20-LVG 45 for OFA-C-D20-LVG	40 W
Mechanical dimension	-	One Full slot width	One Full slot width	One Full slot width

NOTE: OFA-C-D20-MVG in Variable Gain mode supports an extended gain operation of up to 33dB.

Incase of OFA-C-D20-MVG port1 will have same parameters values as OFA-C-D20-LVG and port2 will have parameter values same as OFA-C-D20-VG.