MITSUBiSHI LASER DIODES

ML5XX1A SERIES

FOR OPTICAL INFORMATION SYSTEMS

TYPE

NEME ML5101A, ML5401A

DESCRIPTION FEATURES

• High power (pulse 30mW)

• Single longitudinal mode

• Short astigmatic distance ML5XXl A is a high - power semiconductor laser

whic.h provides a stable, single transverse mode oscillation with emission wavelength of 850nm and

standard light output of 15mW. • Low threshold currrent, low operating current

• Built - in monitor photodiode

• High reliability, long operetion life

APPLICATION

ML5XX1A uses a hermetically sealed package incorporating the photodiode for optical output monitoring. This high - performance, highly reliable, and 10hg -life semi - conductor laser is suitable for

such high - power applications as instrumentation. Laser printer, optical communication, and instrumen-tation

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Conditions Ratings

Po Light output power CW 18

ELECTRICAUOPTICAL CHARACTERISTICS

(Tc = 25

"C)

Symbol Parameter Test conditions

Ith Threshold current CW

lop Operating current CWo Po -15mW

Vo~ Operating voltage CW.Po-15mW

71 Slope efficiency CW.Po=15mW

A P Peak wavelength CW.Po-15mW

Oil Beam divergence angle (parallel) CW.Po-15mW OJ. Beam divergence angle (perpendicular) CW.Po=15mW

1m Monitoring output curren CWo Po = 15mW. VRD = 1 V.

OUTLINE DRAWINGS

+1 o ,..:

2-74

ML5XX1A SERIES

FOR OPTICAL INFORMATION SYSTEMS

16±O.25

Dimensions in mm

Dimensions in mm

Reference slot

3-¢ O. 45±0. 05 P. C. D. ¢ 2. 54

(1 )(3) (2)

• MITSUBISH, I ... ELECTRIC

, A(3)

^Case

II II

S

^LD

(2) (1)

f'I'f!

S

^LD

(2) (1)

SAMPLE CHARACTERISTICS

I

Light output vs. forward current

Typical light output vs. forward current characteristics are shown in Fig.1. The threshold current for lasing is typically 30mA at room temperature. Above the threshold, the light output increases linearly with current, and no kinks are observed in the curves. An optical power of about 15mW is obtained at Ith

+

30 mA.

Because Ith and slope efficiency 7} (dPo/ dlF) is temperature dependent, obtaining a constant output at varying temperatures requires to control the case temperature Tc or the laser current. (Control the case temperature or laser current such that the output current of the built-in monitor PO becomes constant.)

I

Temperature dependence of threshold current (hh) A typical temperature dependence of the threshold current is shown in Fig. 2. The characteristic temperature To of the threshold current is typically 65K in Tc;a; 50"C, where the definition of To is Ith

oc exp (Tc/To).

IJTemperature dependence of shope efficiency A typical temperature dependence of the slope

MITSUBISHI LASER DIODES

ML5XX1A SERIES

FOR OPTICAL INFORMATION SYSTEMS

Fig. 1 Light output vs. forward current

Fig. 2 Temperature dependence of threshold current 70

Fig. 3 Temperature dependence of slope efficiency 0.5

I

Forward current vs. voltage

Typical forward current vs. voltage characteristics are shown in Fig. 4. In general, as the case temperature rises, the forward voltage VF decreases slightly against the constant current IF. VF varies typically at a rate of - 2.0mV /oC at IF = 1 mA.

II

Emission spectra

Typical emission spectra under CW operation are shown in Fig.5. In general, at an output of 10mW, single mode is observed. The peak wavelength depends on the operating case temperature and forward current (output level).

II Te~perature

dependence of peak wavelength A typical temperature dependence of the peak wavelength at an output of CW 15mW is shown in Fig.B.

As the temperature rises, the peak wavelength shifts to the long wavelength side at a rate of about O.25nm/oC typical.

MITSUBISHI LASER DIODES

ML5XX1 A SERIES

FOR OPTICAL INFORMATION SYSTEMS

Fig. 4 Forward current vs. voltage

I

Far-field pattern

The ML5XX1 A laser diodes in fundamental transverse (TEoo) mode and the mode does not change with the current. They have a typical emitting area (size of near -field pattern) of 2.3 x 0.8 ~ m'. Fig.7 and Fig.8 show typical far- field radiation patterns in "parallel" and "perpendicular"

planes.

The full angles at half maximum points (FAHM) are typically 11· and 30· .

II

Pulse response waveform

In the digital optical transmission systems. the response waveform and speed of the light output against the input current pulse waveform is one of the main concerns.

In order to shorten the oscillation delay time. the laser diode is usually biased close to the threshold current.

Figure 9 shows a standard response waveform obtained by biasing ML5XX1 A to Ith and applying a square pulse current (top of Fig.9)up to 15mW.

A quick response is obtained with rising and falling times being both O.3ns typical.

5

_Co

s

.E g .~

i

c::

MITSUBISHI LASER DIODES

ML5XX1A SERIES

FOR OPTICAL INFORMATION SYSTEMS

Fig. 7 Far- field patterns in plane parallel to heterojunction

e / /

o.---r----y----,---,

8 II

0.5

Off- axis angle (deg.)

Fig. 8 Far- field patterns

in plane perpendicular to heterojunction

e

^1.

Off- axis angle (deg.)

Fig. 9 Pulse response waveform

Input pulse

I

tf=250ps

Time (nsec.)

• . MITSUBISHI

. . . . ELECTRIC

^2-77

I

Light output vs. monitoring output characteristic output vs. monitoring photocurrent characteristics.

When the front beam output is l5mW, the monitor output becomes about 1.OmA.

1m

Polarization ratio vs. light output characteristic The main polarization of ML5XX1A is made in the 'direction parallel to the active layer. Polarization ratio refers to the intensity ratio of the light polarized in parallel to the active layer to the light polarized in perpendicular to it. Figurell shows the standard polarizastion ratio vs. total light output characteristic.

The polarization ratio increases with the light output.

• Impedance characteristics

Typical impedance characteristics of the ML5XXl A, with lead lengths of 2mm, are shown in Fig.12

MITSUBISHI LASER DIODES

ML5XX1A SERIES

FOR OPTICAL INFORMATION SYSTEMS

Fig. 10 Light output vs. monitoring output current Fig. 12 Impedance characteristics

---X---1op

2-78

, • ,,' MITSUBISH, I

. . . . ELECTRIC

II

SIN vs. optical feedback ratio

III

Astigmatic distance

There seems to be a difference in luminous point distances thus obtained.

al 1:l

z

MITSUBISHI LASER DIODES

ML5XX1 A SERIES

FOR OPTICAL INFORMATION SYSTEMS

Fig. 13 S/N vs. optical feedback ratio f=20kHz. BW=300Hz. Tc=25-50C 70 50 f=10MHz, BW=300kHz, Tc=25-50'C

60 1 00 Lfj-J'-:-~-:-.I.:c:-:'....,...,.'_,,__:_'_:,...J-~_,J.

o

0.01 0.050.10.2 0.5 1 5 10

MITSUBISHI LASER DIODES

ML5XX3A SERIES

FOR OPTICAL INFORMATION SYSTEMS

TYPE

NAME ML5413A

DESCRIPTION. FEATURES

• High-power, stable single longitudinal mode ML5XX3A is a high - power semiconductor laser

which provides a stable, single transverse mode oscillation with emission wavelength of 820 nm and standard continuous oscillation of 10mW.

• Low threshold current, low operating current

• Built- in monitor photodiode

• High reliabillity, long operation life

APPLICATION

ML5XX3A uses

a

hermetically sealed package incorporating the photodiode for optiocal output monitoring. This high- performance, highly reliable, and long-life semiconductoL laser is suitable for such ·high - power applications as optical disk memory writing.

. Optical disk drive, laser beam printer, optical communication

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Conditions Ratings Unit

Po Light output power CW 25 mW

VAL Reverse voltage (Laser diode)

-

² ^V

VAD Reverse voltage (Photodiode)

-

15 V

IFD ForWard current ( Photodiode)

-

¹⁰ ^mA

Tc Case temperature

-

-40-+60 "C

Tstg Storage temperature

-

-55-+ 100 "C

Dans le document OPTICAL SEMICONDUCTOR DEVICES and (Page 122-129)