FEATURES:

TO-46 tilt window metal can

component, prealigned into SC

Sleeve

Designed for drive currents

between 5 and 15 mA

Optimized for low dependence

of electrical properties over

temperature

High speed

≥1 GHz

Two different laser/ photodiode

polarities

Attenuating coating

Packaged with a photodetector

1.25GBPS 850NM VCSEL

SC TOSA PACKAGE

HFE438X-521

DATA

SHEET

The HFE438x-521 is a high-performance 850 nm VCSEL (Vertical Cavity Surface-

Emitting Laser) packaged for high-speed data communications. This product

combines all the performance advantages of the VCSEL with a custom

designed power monitor diode. The power monitor diode can be used with

appropriate feedback control circuitry to set a maximum power level for each

VCSEL. In addition, built-in power attenuation reduces the effective slope

efficiency. These combined features simplify design for high data rate

communication and eye safety.

Packaged in a fiber receptacle sleeve, this high radiance VCSEL is designed to

convert electrical current into optical power that can be used in fiber optic

communications and other applications. As the current varies above threshold,

the light intensity increases proportionally. Data rates can vary from DC to

above 2 Gb/s.

The HFE438x-521 is designed to be used with inexpensive silicon or gallium

arsenide detectors, but excellent performance can also be achieved with some

indium gallium arsenide detectors (see HFD3381-108).

The low drive current requirement makes direct drive from PECL (Positive

Emitter Coupled Logic) or EML (Emitter Coupled Logic) gates possible and

eases driver design.

The HFE438x-521 is a prealigned and focused fiber optic transmitter designed

to interface with 50/125 and 62.5/125

µm multi-mode fiber.

Part Number

Description

HFE4380-521

SC TOSA with attenuated TO-46 component, VCSEL with Back Monitor

Photodiode, Anode of VCSEL common with Photodiode Cathode

HFE4381-521

SC TOSA with attenuated TO-46 component, VCSEL with Back Monitor

Photodiode, Cathode of VCSEL common with Photodiode Anode