DWDM Wavelength ITU Channels Chart: A Complete Guide (2024)

Initial Published: July 10, 2022

This is the complete guide to Dense Wavelength-Division Multiplexing (DWDM) wavelengths and channels in 2024.

So, if you want to.

• Know the Dense Wavelength-Division Multiplexing (DWDM) basics
• Quickly find the DWDM Wavelength ITU Channels Chart
• Choose the right DWDM transceiver solution

Then, you will enjoy this new complete DWDM wavelength channels guide.

Let’s get started.

#1. DWDM Basics

Dense Wavelength-Division Multiplexing (DWDM) is a dense WDM technology. WDM is a technology to multiplex many optical carrier signals onto a single optical fiber using different wavelengths (colors) of laser light.

DWDM is an evolution of WDM technology. It is a “dense” WDM technology with a much denser wavelength spacing than conventional WDM technologies. Using DWDM technology, we can multiplex up to 80 optical wavelengths onto a single fiber. The figure below shows a basic DWDM system.

#2. What are the benefits of DWDM?

The key benefits of DWDM technology are:

• Increased Capacity: DWDM can multiplex a large number of signals onto a single fiber, which increases the capacity of optical fiber.
• Higher Speeds: DWDM can transmit data at high speeds (up to 100Gbps per channel).
• Increased Distance: DWDM can extend the reach of optical fiber.
• Cost-effective: DWDM is a cost-effective solution for minimizing the total cost of ownership (TCO) of optical fiber networks.

#3. DWDM Wavelength ITU Channels Grid

Depending on the wavelength channel spacing, the International Telecommunication Union (ITU) classifies dense wavelength-division multiplexing into four types: 12.5GHz DWDM, 25GHz DWDM, 50GHz DWDM, and 100GHz DWDM.

The table below shows the different channel spacing of those 4 DWDM wavelength grids.

Comparison	12.5GHz	25GHz	50GHz	100GHz
Wavelength Spacing	0.1nm	0.2nm	0.4nm	0.8nm
Frequencies	193.1 + n×0.0125	193.1 + n×0.025	193.1 + n×0.05	193.1 + n×0.1

The table above shows that the 12.5GHz DWDM requests 0.1nm spacing for each neighboring wavelength, while the 25GHz DWDM requests 0.2nm, the 50GHz DWDM requests 0.4nm, and the 100GHz DWDM requests 0.8nm.

These 12.5GHz and 25GHz DWDM techniques are rarely used due to the narrow wavelength spacing and technical complexity. However, 50GHz and 100GHz DWDM have been widely implemented in long-haul and ultra-long-haul applications due to their lower cost and technological convenience.

Note: When we refer to DWDM wavelengths, we typically mean the 100 GHz DWDM channel.

Today, we will focus only on the 50GHz DWDM and 100GHz DWDM wavelength charts.

#4. 100GHz DWDM Wavelength Channels ITU Grid

ITU Channel	Frequency (THz)	Wavelength (nm)	Wavelength Band	ITU Channel	Frequency (THz)	Wavelength (nm)	Wavelength Band
1	190.10	1577.03	L-Band	41	194.10	1544.53	C-Band
2	190.20	1576.20	L-Band	42	194.20	1543.73	C-Band
3	190.30	1575.37	L-Band	43	194.30	1542.94	C-Band
4	190.40	1574.54	L-Band	44	194.40	1542.14	C-Band
5	190.50	1573.71	L-Band	45	194.50	1541.35	C-Band
6	190.60	1572.89	L-Band	46	194.60	1540.56	C-Band
7	190.70	1572.06	L-Band	47	194.70	1539.77	C-Band
8	190.80	1571.24	L-Band	48	194.80	1538.98	C-Band
9	190.90	1570.42	L-Band	49	194.90	1538.19	C-Band
10	191.00	1569.59	L-Band	50	195.00	1537.40	C-Band
11	191.10	1568.11	L-Band	51	195.10	1536.61	C-Band
12	191.20	1567.95	L-Band	52	195.20	1535.82	C-Band
13	191.30	1567.13	L-Band	53	195.30	1535.04	C-Band
14	191.40	1566.31	L-Band	54	195.40	1534.25	C-Band
15	191.50	1565.50	L-Band	55	195.50	1533.47	C-Band
16	191.60	1564.68	C-Band	56	195.60	1532.68	C-Band
17	191.70	1563.86	C-Band	57	195.70	1531.90	C-Band
18	191.80	1563.05	C-Band	58	195.80	1531.12	C-Band
19	191.90	1562.23	C-Band	59	195.90	1530.33	C-Band
20	192.00	1561.41	C-Band	60	196.00	1529.55	S-Band
21	192.10	1560.61	C-Band	61	196.10	1528.77	S-Band
22	192.20	1559.79	C-Band	62	196.20	1527.99	S-Band
23	192.30	1558.98	C-Band	63	196.30	1527.22	S-Band
24	192.40	1558.17	C-Band	64	196.40	1526.44	S-Band
25	192.50	1557.36	C-Band	65	196.50	1525.66	S-Band
26	192.60	1556.55	C-Band	66	196.60	1524.89	S-Band
27	192.70	1555.75	C-Band	67	196.70	1524.11	S-Band
28	192.80	1554.94	C-Band	68	196.80	1523.34	S-Band
29	192.90	1554.13	C-Band	69	196.90	1522.56	S-Band
30	193.00	1553.33	C-Band	70	197.00	1521.79	S-Band
31	193.10	1552.52	C-Band	71	197.10	1521.02	S-Band
32	193.20	1551.72	C-Band	72	197.20	1520.25	S-Band
33	193.30	1550.92	C-Band	73	197.30	1519.48	S-Band
34	193.40	1550.12	C-Band	74	197.40	1518.71	S-Band
35	193.50	1549.32	C-Band	75	197.50	1517.94	S-Band
36	193.60	1548.51	C-Band	76	197.60	1517.17	S-Band
37	193.70	1547.72	C-Band	77	197.70	1516.40	S-Band
38	193.80	1546.92	C-Band	78	197.80	1515.63	S-Band
39	193.90	1546.12	C-Band	79	197.90	1514.86	S-Band
40	194.00	1545.32	C-Band	80	198.00	1514.09	S-Band

#5. 50GHz DWDM Wavelength Channels ITU Grid

ITU Channel	Frequency (THz)	Wavelength (nm)	Wavelength Band	ITU Channel	Frequency (THz)	Wavelength (nm)	Wavelength Band
1	190.10	1577.03	L-Band	40.5	194.05	1544.92	C-Band
1.5	190.15	1576.61	L-Band	41	194.10	1544.53	C-Band
2	190.20	1576.20	L-Band	41.5	194.15	1544.13	C-Band
2.5	190.25	1575.78	L-Band	42	194.20	1543.73	C-Band
3	190.30	1575.37	L-Band	42.5	194.25	1543.33	C-Band
3.5	190.35	1574.95	L-Band	43	194.30	1542.94	C-Band
4	190.40	1574.54	L-Band	43.5	194.35	1542.54	C-Band
4.5	190.45	1574.13	L-Band	44	194.40	1542.14	C-Band
5	190.50	1573.71	L-Band	44.5	194.45	1541.75	C-Band
5.5	190.55	1573.30	L-Band	45	194.50	1541.35	C-Band
6	190.60	1572.89	L-Band	45.5	194.55	1540.95	C-Band
6.5	190.65	1572.48	L-Band	46	194.60	1540.56	C-Band
7	190.70	1572.06	L-Band	46.5	194.65	1540.16	C-Band
7.5	190.75	1571.65	L-Band	47	194.70	1539.77	C-Band
8	190.80	1571.24	L-Band	47.5	194.75	1539.37	C-Band
8.5	190.85	1570.83	L-Band	48	194.80	1538.98	C-Band
9	190.90	1570.42	L-Band	48.5	194.85	1538.58	C-Band
9.5	190.95	1570.01	L-Band	49	194.90	1538.19	C-Band
10	191.00	1569.59	L-Band	49.5	194.95	1537.79	C-Band
10.5	191.05	1569.18	L-Band	50	195.00	1537.40	C-Band
11	191.10	1568.11	L-Band	50.5	195.05	1537.00	C-Band
11.5	191.15	1568.36	L-Band	51	195.10	1536.61	C-Band
12	191.20	1567.95	L-Band	51.5	195.15	1536.22	C-Band
12.5	191.25	1567.54	L-Band	52	195.20	1535.82	C-Band
13	191.30	1567.13	L-Band	52.5	195.25	1535.43	C-Band
13.5	191.35	1566.72	L-Band	53	195.30	1535.04	C-Band
14	191.40	1566.31	L-Band	53.5	195.35	1534.64	C-Band
14.5	191.45	1565.90	L-Band	54	195.40	1534.25	C-Band
15	191.50	1565.50	L-Band	54.5	195.45	1533.86	C-Band
15.5	191.55	1565.09	L-Band	55	195.50	1533.47	C-Band
16	191.60	1564.68	C-Band	55.5	195.55	1533.07	C-Band
16.5	191.65	1564.27	C-Band	56	195.60	1532.68	C-Band
17	191.70	1563.86	C-Band	56.5	195.65	1532.29	C-Band
17.5	191.75	1563.45	C-Band	57	195.70	1531.90	C-Band
18	191.80	1563.05	C-Band	57.5	195.75	1531.51	C-Band
18.5	191.85	1562.64	C-Band	58	195.80	1531.12	C-Band
19	191.90	1562.23	C-Band	58.5	195.85	1530.72	C-Band
19.5	191.95	1561.83	C-Band	59	195.90	1530.33	C-Band
20	192.00	1561.42	C-Band	59.5	195.95	1529.94	S-Band
20.5	192.05	1561.01	C-Band	60	196.00	1529.55	S-Band
21	192.10	1560.61	C-Band	60.5	196.05	1529.16	S-Band
21.5	192.15	1560.20	C-Band	61	196.10	1528.77	S-Band
22	192.20	1559.79	C-Band	61.5	196.15	1528.38	S-Band
22.5	192.25	1559.39	C-Band	62	196.20	1527.99	S-Band
23	192.30	1558.98	C-Band	62.5	196.25	1527.60	S-Band
23.5	192.35	1558.58	C-Band	63	196.30	1527.22	S-Band
24	192.40	1558.17	C-Band	63.5	196.35	1526.83	S-Band
24.5	192.45	1557.77	C-Band	64	196.40	1526.44	S-Band
25	192.50	1557.36	C-Band	64.5	196.45	1526.05	S-Band
25.5	192.55	1556.96	C-Band	65	196.50	1525.66	S-Band
26	192.60	1556.56	C-Band	65.5	196.55	1525.27	S-Band
26.5	192.65	1556.15	C-Band	66	196.60	1524.89	S-Band
27	192.70	1555.75	C-Band	66.5	196.65	1524.50	S-Band
27.5	192.75	1555.34	C-Band	67	196.70	1524.11	S-Band
28	192.80	1554.94	C-Band	67.5	196.75	1523.72	S-Band
28.5	192.85	1554.54	C-Band	68	196.80	1523.34	S-Band
29	192.90	1554.13	C-Band	68.5	196.85	1522.95	S-Band
29.5	192.95	1553.73	C-Band	69	196.90	1522.56	S-Band
30	193.00	1553.33	C-Band	69.5	196.95	1522.18	S-Band
30.5	193.05	1552.93	C-Band	70	197.00	1521.79	S-Band
31	193.10	1552.52	C-Band	70.5	197.05	1521.40	S-Band
31.5	193.15	1552.12	C-Band	71	197.10	1521.02	S-Band
32	193.20	1551.72	C-Band	71.5	197.15	1520.63	S-Band
32.5	193.25	1551.32	C-Band	72	197.20	1520.25	S-Band
33	193.30	1550.92	C-Band	72.5	197.25	1519.86	S-Band
33.5	193.35	1550.52	C-Band	73	197.30	1519.48	S-Band
34	193.40	1550.12	C-Band	73.5	197.35	1519.09	S-Band
34.5	193.45	1549.72	C-Band	74	197.40	1518.71	S-Band
35	193.50	1549.32	C-Band	74.5	197.45	1518.32	S-Band
35.5	193.55	1548.91	C-Band	75	197.50	1517.94	S-Band
36	193.60	1548.52	C-Band	75.5	197.55	1517.55	S-Band
36.5	193.65	1548.11	C-Band	76	197.60	1517.17	S-Band
37	193.70	1547.72	C-Band	76.5	197.65	1516.78	S-Band
37.5	193.75	1547.32	C-Band	77	197.70	1516.40	S-Band
38	193.80	1546.92	C-Band	77.5	197.75	1516.02	S-Band
38.5	193.85	1546,52	C-Band	78	197.80	1515.63	S-Band
39	193.90	1546,12	C-Band	78.5	197.85	1515.25	S-Band
39.5	193.95	1545.72	C-Band	79	197.90	1514.87	S-Band
40	194.00	1545.32	C-Band	79.5	197.95	1514.49	S-Band

#6. FAQs about DWDM Wavelength Channels

Q: What is the difference between 50GHz and 100GHz DWDM wavelengths?

The main difference between 50GHz and 100GHz DWDM wavelengths is the channel spacing. 100GHz DWDM wavelength has 0.8nm spacing, while 50GHz only has 0.4nm spacing. 50GHz DWDM transceiver optics must ensure a minor wavelength drift to avoid crosstalk between two adjacent wavelengths.

Q: What is the maximum wavelength channel for the DWDM system?

The max wavelength channel for the DWDM system is determined by the spacing between two adjacent wavelength channels. For example, in a 50GHz DWDM system, the spacing between two adjacent channels is 0.4nm. So, the max wavelength channel can achieve 160 channels, while the typical 100GHz DWDM channel is 80 wavelength channels.

Q: What is the difference between DWDM and CWDM?

The main difference between DWDM and CWDM is the spacing between wavelength channels. DWDM has a narrower channel spacing than CWDM.

For example, in DWDM, the spacing between channels can be as low as 0.4nm, while in CWDM, it is usually 20nm or more. That results in different bandwidth capacities for both technologies. DWDM can transmit up to 80 channels in a single fiber, while CWDM can only manage 8 or 18 channels.

Q: With so many wavelengths, how do I reduce DWDM inventory and lead time?

There are two suggestions. The first is to choose the Tunable transceiver optics, which can work on multiple DWDM wavelengths. Just set the wavelength on-demand, and you don’t have to struggle with DWDM modules that don’t have wavelengths in stock.

The second is to choose the DWDM optics supplier that has a huge stock and can offer you a short lead time. Optcore is a supplier with 10000+ optics in stock and 1-3 days lead time for most DWDM SFP and SFP+.

Q: What is DWDM center frequency deviation?

Center frequency deviation is defined as the difference between the standard center frequency and the actual center frequency. The channel spacing is relatively narrow in dense wavelength division multiplexing (DWDM) systems, meaning that even a slight offset can significantly impact performance. As a result, the ITU-T Recommendation specifies that a channel’s center frequency deviation should generally be less than 10% of its frequency.

#7. Optcore DWDM Transceiver Solution

Optcore provides a comprehensive DWDM transceiver solution, including DWDM SFP, DWDM SFP+, DWDM XFP, Tunable SFP+, Tunable XFP, and DWDM SFP28 optics. These DWDM optical transceivers comply with the MSA standard and have been extensively tested to work with all major brands’ switches and routers.

Part #	Product Description	Data Rate	Wavelength	Distance	Channel Spacing
OPD10G-xx40DCR	DWDM SFP+ ER	10Gbps	C17-C61	40km	100GHz
OPD10G-xx80DCR	DWDM SFP+ ZR	10Gbps	C17-C61	80km	100GHz
OXD10G-xx40DCR	DWDM XFP ER	10Gbps	C17-C61	40km	100GHz
OXD10G-xx80DCR	DWDM XFP ZR	10Gbps	C17-C61	80km	100GHz
OPD1250-xx80DCR	DWDM SFP ZX	1Gbps	C17-C61	80km	100GHz
OPD1250-xxA2DCR	DWDM SFP EZX	1Gbps	C17-C61	120km	100GHz
OPD2488-xx80DCR	SDH DWDM SFP ZX	2.5Gbps	C17-C61	80km	100GHz
OPD2488-xxA2DCR	SDH DWDM SFP EZX	2.5Gbps	C17-C61	120km	100GHz
OPD10G-TD80DCR	Tunable SFP+ ZR	10Gbps	Tunable	80km	50GHz
OXD10G-TD80DCR	Tunable XFP ZR	10Gbps	Tunable	80km	50GHz

#8. Final Words

This article provides a complete guide to the DWDM wavelength ITU channels chart in 2024. We have explained the different types of DWDM wavelength grids and their associated channel spacing. We have also answered some frequently asked questions about DWDM wavelength channels.

Now I’d like to hear from you:

Have you ever used any DWDM transceivers?

Do you have any experience with DWDM systems?

Will you perfer 100GHz DWDM or 50GHz DWDM?

Do you know how to set the tunable SFP+ wavelength?

Either way, let me know by leaving a comment below right now.

Read more:

• Do You Know the CWDM Transceiver Color Code?
• Introduction to DWDM
• OPTCORE Best 10G CWDM SFP+ Transceiver Solution
• Optical Wavelength Band 101: Definition, Classification and Application

Reference:

• Spectral grids for WDM applications: DWDM frequency grid