What people will do on Qingming Festival (also called Tomb Sweeping day)?

Qingming Custom:

Qingming is an important traditional Chinese festival also known as Tomb-Sweeping Day. This festival reminds us the importance of the family members in our lives which is one of the beauty of Chinese culture.

During Qingming, Chinese families visit the tombs of their ancestors to clean the gravesites, pray to their ancestors, and make ritual offerings. 

The holiday recognizes the traditional reverence of one's ancestors in Chinese culture. 

Now chinese people is changing, Vigorously promote the "flower sacrifice sweep", "planting tree sacrifice sweep", "online sacrifice sweep", "community public sacrifice", "collective public sacrifice" and "family memorial service" and other healthy and civilized ways, expressing sympathy and admiration for the ancestors, reducing the environment for the mountains Pollution and fire hazards, maintaining a good ecological environment for green mountains and green hills.

China's fifth solar term, Clear and Bright, will begin on April 5, which coincides with a traditional Chinese festival, Qingming Festival, or Tomb-Sweeping Day.

The festival also marks a change in the weather, as temperatures begin to rise nationwide and rainfall increases, making it a crucial time for plowing and sowing in the spring.

《清明》 

 (唐)杜牧 

 清明时节雨纷纷，路上行人欲断魂。 

 借问酒家何处有？牧童遥指杏花村。 

 ( 杨宪益、戴乃迭英译《清明》((无韵译法) （古诗苑汉英译丛《唐诗》，外文出版社，2001） ) 

 It drizzles endless during the rainy season in spring, 

 Travelers along the road look gloomy and miserable。 

 When I ask a shepherd boy where I can find a tavern, 

 He points at a distant hamlet nestling amidst apricot blossoms。 

Dear All Customer,

Please kindly note that we will have Tomb Sweeping Festival Holiday from April 5th to 7th.

We will back to work on 8th April, 2019. Any urgent things on optical transceiver order, OTN optical Transmission, Protection and Monitoring solution, can contact us by email. Our sales team will reply you ASAP.

Contact Ivy: sales6@htfuture.com

Best regards,

HTFuture team

What is LSZH optical cable?

Since 1970, the wire and cable industry has used low-smoke, low-halogen materials in many areas. 
As the improvements of environmental awareness and safety issues, made people realize that wires and cable jackets play a very important role in fires,
And have led to the widespread adoption of low-smoke, Zero halogen (LSZH) optical cable.

But what is the LSZH? 
LSZH optic cable is a kind of optical fiber cable with sheath and insulation which is made of special LSZH material.
When it fired, just produce less smoke, so it can be a very ideal choice for many place when build the facilities.

lszh optical cable

Which field it used for?
The most important feature of the LSZH is the safety, Low smoke and zero halogen is very important and beneficial for the personal safety.
LSZH cables are used in public places such as trains and metro stations, airports, hospitals, ships and commercial buildings, 
Data centers contain a large number of fiber optic cables, and often enclosed spaces with cooling systems that can potentially distribute by-products of combustion into a large area.

In the event of a fire, many people die of inhalation of smoke, much more than other causes of death in a fire.

So for personal safety, it is important to use LSZH cables that release very little smoke and zero halogen material in these locations.

LSZH CABLES

When choosing or designing a fiber optic cable for any application,
The operational environment which used in, must be taken into account in terms of effectiveness, performance and price, among other things. 
And when safety and the environment are a factor, and considering high performance and capacity, the LSZH cable is the product you must specify at this time.

Any question, welcome to contact Ivy: sales6@htfuture.com

HTFuture LSZH cable

How to avoid mistakes in Fiber Optical transceivers Installation?

When install a Optical fiber optic network, people may make some common mistakes, which were usually overlooked. HTFuture list the most common ones. Hope to give you some guidance for your optical network installation.

1. SFP BIDI transceiver must be used in pair
The SFP BiDi transceiver must be matched correctly. Take an example: The paired BIDI transceivers connect with switch A and switch B. If the switch A connect with TX1310/RX1550nm module, the switch B must be a TX1550/RX1310nm module. The TX1550/RX1310nm module is more expensive than the TX1310nm/RX1550nm one due to the cost of their more powerful lasers. So some network engineers may hope to save money by installing two TX1310nm/RX1550nm. But it doesn’t work. 

2. Understand All kinds of Fiber connectors First
Optical transceivers use a variety of connectors, so make clear their differences before you begin ordering products for a fiber installation is necessary. SC (stick and click) is a square connector. ST (stick and twist) is a round, bayonet-type. LC connectors look like a compact version of the SC connector. It's half the size of SC. SFP transceivers usually use LC connector.  Less common connectors include FC, MT-RJ and E2000.

3. Don’t Use APC connector with UPC Connector
Fiber connections may use Angle Polished Connectors (APC) or Ultra Polished Connectors (UPC), and they are not interchangeable. There are physical differences in the ferules at the end of the terminated fiber within the cable (shown in the figure below). An APC ferrule end-face is polished at an 8° angle, while the UPC is polished at a 0° angle. If the angles are different, some of the light will fail to propagate.

4. Don’t Connect SFP to SFP+ Transceivers
Standard SFP typically support speeds of 100Mbps or 1Gbps. XFP and SFP+  support 10Gbps connections. SFP+  is smaller than XFP and allows for greater port density. Though the size of SFP and SFP+  is the same, you can’t connect SFP+  to a device (SFP) that only supports 1 Gbps.

Have you made these mistakes before when fiber optic network installation? Hope today’s sharing will help you! Make your work more efficient.

HTFuture aim to be your Reliable Partner for different kinds of Compatible transceiver (QSFP28, QSFP+, SFP, XFP, SFP+ etc) | OTN optical transmission system | DWDM Mux Demux | OADM | OTU | EDFA | NMS | DCM | OLP | OBP etc |  More information, welcome to contact Ivy or skype: sales6@htfuture.com 

APC VS UPC optical patch cord, which one to choose?

When talking about passive products, like patch cord, pigtail, adapter and splitter, will involve UPC and APC description. Some people may be curious. For example, what is LC/UPC - LC/UPC? What is SC/APC - SC/APC? In fact, UPC and APC are two grinding methods for optical fiber bushings. Today we will mainly introduce these two different grinding methods for you to choose the right solution for the network center.

What is UPC&APC?
Install connectors on one fiber end face, return loss is unavoidable, this is due to the reflection of the optical source. Serious optical loss will damage the laser optical source and interrupts the transmission of signals. Therefore, connector rings with different grinding methods can avoid severe echo loss to a certain extent. UPC and APC are two widely used grinding types.

UPC, ultra physical contact, evolved from PC and has better surface finish. UPC connector depends on machine polishing, low return loss.

APC, angular physical contact. The end face is drawn to a 8 degree angle, which is beveled to reduce reflection. APC can only be connected to APC. Since the structure of the APC is completely different from the UPC, if the two connectors are connected with a flange, the optical fiber end of the connector will be damaged.

How to distinguish UPC and APC?
Different end face. The UPC connector is polished without angles, but the APC connector has an angle of 8 degrees.
Optical reflection mode. The UPC connector will reflect any reflected light back into the light source in use, but the APC connector reflects the reflected light at a certain angle to the cladding rather than directly to the light source.
Return loss. The APC connector provides -65 dB return loss, the UPC is -50 dB. If the return loss is low, the connector can achieve better matching performance.
Connector color. The UPC connector is usually blue, while the APC connector is usually green.


When choosing an optical patch cord, it should be based on your actual application. APC connector performance is better than UPC. APC is best suited for high bandwidth applications and long distance links. Such as FTTx, passive optical network(PON) and Wavelength division multiplex(WDM) are more sensitive to return loss. Therefore, the APC is a better solution for providing the lowest return loss. However, extensive use of APC connectors will increase costs considerably. If the return loss requirement is not high, the UPC is a better choice.

HTFuture provides APC, UPC and other types of fiber optic jumper, low loss, cost-effective, is the best choice for optical communications cabling.

Optical patch cord

HTFuture aim to be your Reliable Partner for different kinds of Compatible transceiver (QSFP28, QSFP+, SFP, XFP, SFP+ etc) | OTN optical transmission system|DWDM Mux Demux|OADM | OTU | EDFA | NMS | DCM | OLP | OBP etc| More information, welcome to contact Ivy or skype: sales6@htfuture.com 

Quickly understand the difference of CWDM and DWDM technology

Some customers are asking for the difference of the CWDM and DWDM technology.

CWDM and DWDM both use the Wavelength Division Multiplexing (WDM) technology, but with different features. As shown in the below picture, there is a comparison between CWDM and DWDM technology. A CWDM MUX/DEMUX deals with small amounts of wavelengths, only up to 18 CWDM wavelength, but with large spans between wavelengths (spaced typically at around 20nm, from 1270 nm to 1610 nm). 

A DWDM MUX/DEMUX deals with narrower wavelength spans (no more than 0.8nm, 0.4nm or perhaps 0.2nm), and may accommodate 40,80, or even 160 wavelengths(mostly used is Channel 17 to Channel 61 wavelength).

HTFuture can provide you the full range of CWDM DWDM products that you need. If there is any inquiry, just let me know please. Ivy: sales6@htfuture.com

CWDM DWDM MUX DEMUX

What's the main raw materials for optical transceiver?

The main components of the product are optoelectronic devices(TOSA,ROSA,BOSA), shell (optical interface) and PCBA.
  
◆ TOSA(Transmitting Optical Sub-Assembly), with 4 PINS; ROSA(Receiving Optical Sub-Assembly), with 5 PINS; BOSA(Bi-Directional Optical Sub-Assembly), with 9 PINS.

◆ PCBA is a circuit board. Engineers will select the different chip design according to the projects. The common chips are SEMTECH, UXUN, Maxim and Macom.

◆ The optical module shell is generally divided into single and dual fiber. According to the interface type, mainly divided into LC and SC.

Different types of optoelectronic devices, the raw materials are not exactly the same, as follows:
TOSA: TO-CAN, ceramic cores, tube(Metal in general)
Classification of ceramic cores
※ Precision: single mode ceramic core and multimode ceramic core
※ outside diameter: SC(2.5mm) , LC(1.25mm)

Major chip manufacturers: 
Japan: Mitsubishi, Sumitomo
USA: CY（CYoptics）, AOI
Taiwan: LuxNet, Truelight

ROSA: PIN-TIA 、tube(Plastic in general)
PIN-TIA chip manufacturers:
Domestic: Fiberhome, Mignal, Opto Sensor Tech
Abroad: NT(Nanotech), Oclaro, SEMTECH etc.

BOSA: TO-CAN, ceramic cores, tube and filters

HTFuture aim to be your Reliable Partner for different kinds of Compatible transceiver (QSFP28, QSFP+, SFP, XFP, SFP+ etc) | OTN optical transmission system|DWDM Mux Demux|OADM | OTU | EDFA | NMS | DCM | OLP | OBP etc| More information, welcome to contact Ivy or skype: sales6@htfuture.com 

What's the difference between G652,G657A,G655 and G654 fiber?

Optical cables are made to meet the optical, mechanical or environmental performance specifications.It is a communication cable assembly that can be used individually or in group. Active Optical cable is the main transmission tool of various information network in the society.

Optical cable is consist of core, coating and jacket.
Core: Higher refractive index, for transmitting light;
Coating: Lower refractive index, form a total reflection condition with core;
Jacket: High strength, can bear greater impact, protect optical fiber.

Common optical fiber and differences:

G652: Standard single mode fiber, zero dispersion point is in 1300nm,divides into G652A,B,C,D.The main difference is PMD. It’s feature is that the fiber dispersion is very small when working wavelength is 1300nm, the transmission distance of the system is only limited by the loss;

G657A: Available in D, E, S, C and L5 wavebands. It can work in the whole working wavelength range of 1260-1625nm. With excellent bending performance and the technical requirements of geometric size are more accurate;

G655: Non zero dispersion-shifted fiber (NZ-DSF) contains 655A,B,C; The main characteristic is that the dispersion of 1550nm is close to zero, but not zero. It is an improved dispersion-shifted fiber to suppress four-wave mixing;

G654:Ultra low loss optical fiber, mainly used for transoceanic optical cable. The common core is pure SiO2,while the ordinary ones need to be doped with germanium. The loss near 1550nm is minimum, only 0.185dB/km, the dispersion is relatively large,a bout 17～20 ps/(nm·km), But the dispersion is zero in the 1300nm wavelength region.

We can see from above that their difference on fiber types, dispersion and loss .

HTFuture aim to be your Reliable Partner for different kinds of Compatible transceiver (QSFP28, QSFP+, SFP, XFP, SFP+ etc) | OTN optical transmission system|DWDM Mux Demux|OADM | OTU | EDFA | NMS | DCM | OLP | OBP etc| More information, welcome to contact Ivy or skype: sales6@htfuture.com