FAQ

A brief comparison as follows.

VCSEL (Vertical Cavity Surface Emitting Laser)	EEL (Edge Emitting Laser)
Circular beam	Elliptical beam
Low threshold current ( < 8 mA )	High threshold current ( 10 ~ 50 mA )
Low power consumption	Heat sink is necessary
Low temperature-sensitivity	High temperature-sensitivity
High reliability ( MTTF > 107 hours )	Long life, MTTF105 ~ 106 hours
High coupling efficiency ( > 50% )	Corrective optics is necessary
Easy alignment and packaging	High alignment and packaging cost
High-density 2-D arrays workable	High alignment and packaging cost
Narrow beam divergence	Wide beam divergence

VCSEL, or Vertical Cavity Surface Emitting Laser, is a semiconductor micro laser diode that emits cylindrical beam light vertically from the surface of a fabricated wafer. This special characteristic enables it to offer significant advantages over edge-emitting lasers (EEL) currently used in most fiberoptic communication devices or other light source used in general purpose.

High quality and low cost

(1) Low threshold current and then low power consumption, lowering your energy budget.
(2) Good temperature dependence.
(3) High reliability, the MTTF at room temperature operation is over 107 hours.
(4) radiation hard.
(5) Competitive price.
(6) Very low cost products with epoxy molding.
 

TrueLight has VCSEL products of infrared 780 nm and 850 nm emission in 1999.

For communication-grade VCSEL, the output power of VCSEL chip and components is typically 1 ~ 3 mW at 12 mA operation. Powers of < 1.0 mW and > 3.0 mW at 12 mA operation are optional and available by special order. The output power range of our VCSEL transmitter is 0 ~ -4 dBm and -4 dBm ~ -8 dBm for your option. For general application purpose, the power could be 1 ~ 10 mW with bias current from 10 mA to about 30 mA. Please specify your requirement, and contact at sales@truelight.com.tw. Or use "Contact Us".

TrueLight provides two options of device specifications. The communication-grade device has low threshold and moderate power output, the threshold current is typical 3 mA. The general-grade device might have higher threshold current and can be operated at higher bias current.

The beam divergence of our VCSEL chip is typical of 8o. The VCSEL components are from 1.5o ~ 16o depend on the package configuration.

The series resistance of our VCSEL is 40 ohm typically. The range is 30~60 ohm. You are reminded to incorporate the inherent series resistance in your circuit design.

The VCSEL is a high speed laser diode. However, it can meet many requests of transmission speed. They can be used in below 10 Mbps, 100 Mbps, 155 Mbps, 622 Mbps and 1.25 Gbps, and even 2.5 Gbps applications.

The rise and fall time of our VCSEL transmitter is between 100~140 ps and 160~220 ps, respectively. They meet the requirement of gigabit speed. 
VCSEL and PIN OPTICAL LINKS(214 KB)    

The MTTF our VCSEL is over 107 hours at 25oc, 10mA operation, please download the "Reliability Data of 850 nm VCSEL "for a reference document.
Reliability Data of 850 nm VCSEL(214 KB)

Please click "Temperature-Sensitivity" for a reference document..
Temperature-Sensitivity(214 KB)

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