<PAGE>

                                 EXHIBIT 01.2
Promissory Note - Daryl Eigen and Oplink Communications - March 27, 2001

PROMISSORY NOTE
$160,000 March 27, 2001
FOR VALUE RECEIVED, the undersigned, DARYL J. EIGEN, hereby unconditionally
promises to pay to the order of OPLINK COMMUNICATIONS, INC., a Delaware
corporation ("Oplink", the "Company" or "Holder"), at such place as Holder
hereof may designate, in lawful money of the United States of America and in
immediately available funds, the principal sum of $160,000 together with simple
interest accrued from the date hereof on the unpaid principal at the rate of
8.50% per annum, calculated on the basis of a 365-day year for the actual number
of days elapsed.

1. Principal Repayment. The outstanding principal amount and any accrued and
unpaid interest hereunder shall be due and payable in one lump sum on the first
anniversary of the date hereof; provided, however, that in the event that the
undersigned's employment with the Company is terminated the entire principal
balance and all accrued interest shall become immediately due and payable, and
immediately collectible by Holder pursuant to applicable law (the "Maturity
Date").

2. Prepayment. This Note may be prepaid at any time without penalty. All money
paid toward the satisfaction of this Note shall be applied first to the payment
of interest as required hereunder and then to the retirement of the principal.

3. Escrow; Full Recourse Note. This Note is secured by an escrow (the "Escrow")
comprising all of the shares of Oplink common stock covered by the employee
stock option granted to the undersigned in connection with his employment with
the Company (the stock option referred to as the "Stock Option"). As the Stock
Option vests from time to time, the Oplink shares so vested shall be placed into
the Escrow and, if the undersigned elects to purchase any of such shares, the
shares so purchased shall, as part of the Escrow, be pledged by the undersigned
in favor of the Holder pursuant to a Stock Pledge Agreement in substantially the
same form as that attached hereto. If the undersigned wishes to sell any of the
Oplink stock so purchased before the Maturity Date, the proceeds realized
therefrom shall first be applied to prepay this Note until it is settled in
full. In the event that the undersigned's employment with the Company is
terminated, should any principal amount or any accrued and unpaid interest
under this Note remain due and payable, Holder has the right (but not the
obligation) to require the undersigned to sell any or all of the Oplink common
stock in the Escrow immediately and to apply the proceeds realized therefrom to
repay this Note until it is settled in full. The undersigned shall be solely
responsible for any tax consequences to him arising from his optioned shares
being so escrowed, pledged and/or sold, as the case may be. Notwithstanding the
foregoing, this Note is full recourse, accordingly, Holder shall be entitled to
seek personal judgement against the undersigned in the event of a default for
the full amount of the principal and accrued interest then outstanding, plus any
costs or expenses as provided herein.

4. Non-Consumer Debt. The undersigned hereby represents and agrees that the
amounts due under this Note are not consumer debt, and are not incurred
primarily for personal, family or household purposes, but are for business and
commercial purposes only.
<PAGE>

Promissory Note - Daryl Eigen and Oplink Communications - March 27, 2001

5. Waiver. The undersigned hereby waives presentment, protest and notice of
protest, demand for payment, notice of dishonor and all other notices or demands
in connection with the delivery, acceptance, performance, default or endorsement
of this Note.

6. Expenses; Attorneys' Fees. The Holder hereof shall be entitled to recover,
and the undersigned agrees to pay when incurred, all costs and expenses of
collection of this Note, including without limitation, reasonable attorneys'
fees.

7. Governing Law. This Note shall be governed by, and construed, enforced and
interpreted in accordance with, the laws of the State of California, excluding
conflict of laws principles that would cause the application of laws of any
other jurisdiction.

/S/ DARYL J. EIGEN
_________________________________________
DARYL J. EIGEN

ACCEPTED BY OPLINK COMMUNICATIONS, INC.:

/S/ JOSEPH Y. LIU
__________________________________________
JOSEPH Y. LIU